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The myth of poor Democratic performance in House races in the 2008 election

There’s an idea going around that the Democrats turned in a disappointing performance in Congressional races this year. For example, a politically-minded friend of mine of the liberal persuasion wrote: “The election was good news, although the Democrats did not do quite as well in the Senate and House as I expected. Obama did not have very long coattails–given how anti-Republican Americans are these days.”

Some of the pros say this too; for example, Charlie Cook writes, “given the strength of the top of the ticket nationally, one might have thought that the victory would have been more vertically integrated. . . . what happened down-ballot was not proportional to what happened at the top.”

And Mickey Kaus attributes this to moderate ticket-splitters who, expecting that Obama would win, decided to support Republicans in Congress: “swing voters compensated for the bold, hopeful risk they took on Obama (including for overcoming any race prejudice) by gravitating back toward Republicans in their local Senate and House races.”

The only trouble with this theory is that it’s not supported by the data. Obama won 53% of the two-party vote, congressional Democrats averaged 56%. The average swing of 5.7% from Democratic congressional candidates in 2004 to Dems in 2008 was actually greater than the popular vote swing of 4.5% from Kerry to Obama.

Let’s look at what happened state by state. Here I’m plotting the swing in average district vote in each state, comparing the congressional elections of 2004 to those of 2008, ordering the states by Kerry’s share in 2004:


The horizontal blue line shows the average swing of 5.7%. The Democrats gained in nearly every state, with, unsurprisingly, some big swings in some of the small states that have only one or two congressional districts. Now let’s compare this to the state-by-state swing in the presidential vote:


Obama beat Kerry nearly everywhere, fairly uniformly with only a few exceptions–we knew that–but my point here is that Obama’s swings weren’t quite as large, on average, as the state congressional delegations’.

If you want, you can look at both swings at once:


In the states in the upper left of this graph, the Democrats improved more in the congressional than in the presidential vote; the states in the lower right are those where the Obama-Kerry swing was greater than the Democrats’ swing in House races.

There are a lot more states in the upper left than in the lower right. Each state has its own story–for example, I wouldn’t attribute Don Young’s squeaker in Alaska to Barack Obama’s coattails–but given the graphs above, I think it’s hard to make the case that, overall, the voters were saying No to the Democrats in Congress. On the contrary, congressional Democrats averaged 56% of the vote–their best showing since 1976 (and far more than the Republicans’ 52% in 1994).

Here’s the story in a map:


For some historical perspective, here are the Democrats’ two-party vote share in presidential elections and average two-party vote in congressional elections since 1946:


Presidential voting has been much more volatile than congressional voting (incumbency and all that). This makes the Democrats’ 5.7-point gain over two elections even more impressive.


I think Charlie Cook was closer to the mark when he wrote, “The political environment and momentum that Democrats seemed to have in recent months may have led to an unrealistic set of expectations. In this, perhaps we pundits share some blame.” I don’t think it makes a lot of sense to consider Obama’s 53% “enormously impressive” and congressional Democrats’ 56% a disappointment.

The data demolish the idea that voters in 2008 were pulling the lever for Barack but not for the Dems overall (not for “Nancy Pelosi,” if you will).


1. I thank John Kastellec and Jared Lander for gathering the data and sharing their thoughts.

2. I’m counting uncontested House candidates at 75% of the vote (see our earlier article for discussion of this and similar technical issues).

3. We use average district vote rather than total vote because congressional vote totals vary a lot, and we’re trying to assess national public opinion (as judged, for example, in Kaus’s quote above).

4. The Democrats won resoundingly; this means that the voters preferred them to the alternative; it does not necessarily mean the voters want the specific policies proposed by the Democrats. Recall the Democrats’ surprising lack of popular success after 1976 and the Republicans’ struggles after their 1994 sweep. 5. I’m talking about public opinion here, not campaign strategy. I’m sure that Democratic leaders were disappointed in their party’s performance in key congressional races, especially given their immense financial resources this year. At the level of public opinion, though, the Democrats in Congress outperformed Obama overall and in 38 states–and their swing beat Obama’s overall and in 32 states–so I think you’d be hard pressed to argue that the voters were balancing toward the Republicans in congressional voting. This is not to say that the voters have given the Democrats a blank check, but it really was a Democratic swing, not an Obama swing.

P.S. More graphs here.

P.P.S. Kaus replies (via blog):

I don’t understand Andrew Gelman and Matt Yglesias’ point. You don’t win the House of Representatives when you rack up a large percentage of the national “two party “Congressional vote, or when you win a large “average swing” vote on a “state-by-state” basis. You win when you win lots of actual House seats. That’s what can pass or defeat legislation. And measured by actual House seats the Democratic gains (of about 22) were a little less than expected. There is a reason for this.

My response:

1. As noted here, I think the appropriate comparison is 2004 to 2008. Obama did 4.5 percentage points better than Kerry; congressional Democrats averaged 5.7 percentage points more of the vote than their counterparts in 2004. And the Democrats gained many more than 22 House seats since 2004.

2. See my point 5 above. I’m willing to believe that the Democrats’ campaign strategy had problems, or that they underperformed in marginal districts. But, to return to Kaus’s original point about ticket splitters: “maybe there was a determined effort to apply checks and balances. By deciding to elect Obama president, more than a few voters may have opted to keep the Republican incumbent in place, just to prevent Democrats from getting carried away.” I don’t see it. If you want to talk about motivations of voters, I think it makes the most sense to look at vote shares, not just winners.

3. I don’t understand why Kaus puts “two party” and “state-by-state” in quotes. I mean, I guess I do understand, since he’s quoting me (which I appreciate), but I feel like he’s trying to say there’s something fishy about these ideas. But there’s not. “Two party” vote share just means that we exclude third parties and focus on the competition between the Democrats and Republicans. (That’s why, for example, I don’t think it makes sense to compare Obama’s 52% of the total vote to Reagan’s 50%-ish of the total vote in 1980. Reagan competed in a three-candidate race and he did much better than his main opponent, Carter.) I did my “state-by-state” analysis in order to compare Obama’s swing to congressional swings in different places.

To summarize: if the question is campaign strategy–did the Democrats do all they could’ve, or did the Republicans play a poor hand suprisingly well–then, yes, by all means, compare the election outcome to Stu Rothenberg’s and Charlie Cook’s pre-election forecasts. But if you are interested in public opinion–for example, were the voters trying to balance Obama with a more Republican congress–then I think vote swings are more informative.

I think Kaus and I could probably agree that there are two separate questions: (1) Did the voting public favor congressional Democrats (as compared to how they voted for Obama), and (2) Did the Democrats do worse in 2008 than they should have, given their lead in public opinion? I think the answer to (1) is pretty clear: the voters swung toward the Democrats in congress as well as (actually slightly more than) in presidential voting. I have no idea about (2), and I’d defer to Charlie Cook and others on this question. I’m less interested in question (2) but I agree with Kaus that such questions are important, as they affect the size of the Democrats’ majority in both houses.

P.P.P.S. Election outcome compared to anticipated seats-votes curve here.


  1. Sherman Dorn says:

    The next extension of this is to look at state legislative races. I know Florida would still be underperforming compared to the top of the ticket, but I’m curious about other places.

  2. Kevin Maley says:

    Trends in democratic “improvement” can also be understated by such maps and graphs by making it an either-or. For example in states like Massachusetts, improvement is nearly impossible as the entire congressional delegation (every House member and Senator) is a democrat.

  3. Chris says:

    Arkansas is an outlier again, I notice. The outlier status of AK, HI, and AZ has obvious explanations, but what the heck is going on in Arkansas?

    Also, the hurricane explanation for Obama’s poor performance in LA seems called into question by the fact that Democrats in the House did pretty well there. Unless many of the displaced voters would have been Obama Republicans, I don’t see how displacement explains the data.

  4. […] Gelman looks at The myth of poor Democratic performance in House races in the 2008 election at Red State, Blue State, Rich State, Poor State: Obama won 53% of the two-party vote, […]

  5. hellx says:

    Nice job of illustrating with statistics what one could see early on election night: decisive wins by Democrats in races that were decided long before the presidential race in those states.

  6. Jonrysh says:

    The Republicans had a majority of votes for U.S. Representatives only in 1994 and 2002 (if I read the chart right), but they controlled the House from 1994 till 2006. There must be some kind of bias. Overrepresentation of small states? Gerrymandering?

  7. […] Lots of math and analysis here debunks the myth that people only voted for Obama, not for down-ticket races. Krugman pointed out that if you combine the 2006 and 2008 elections, the “Democratic Revolution” that we just had way, way outstripped the “Republican Revolution” in 1994, and we (as progressives) need to keep saying that. There are commentators already saying that the US is really a “Center-right” country, and perpetuating the myth debunked in the link above. This is simply not true, based on the information that we have. The left/center-left was up in this election, and they won convincingly. Obama didn’t run away from his plans to increase taxes on the wealthiest people to pay for government programs to help those less fortunate. People knew what they were getting into when they elected him, so we can’t let the storyline be seized by commentators wishing it were some other way. […]

  8. […] Krugman highlights the work of Andrew Gelman, who demonstrated that congressional Democrats averaged 56% of the two-party vote, while Obama […]

  9. Andrew says:

    Jonrysh: Yes, overrepresentation of small states, also incumbency advantage, also just the patterns that happen to arise because voters are not distributed geographically at random.

  10. […] by gravitating back toward Republicans in their local Senate and House races.” In reality, as Andrew Gelman shows, there was a strong uniform swing toward the House […]

  11. Steve Sailer says:

    The updating of the Voting Rights Act that came into effect with the redistricting following the 1990 Census helped the Republicans out because it required the creation of minority majority districts in order to get more minority Congressmen elected. The GOP happily favored this because it required stuffing large numbers of fervently Democratic minorities into a few districts, leaving Republicans with moderate majorities in a lot of districts. Thus, the GOP could control the House in 1996, 1998, and 2000 despite losing the overall House vote.

    This GOP strategy of gerrymandering districts to give them narrow majorities in most districts only works if the overall vote is close. In 2006, it wasn’t, so they lost a large number of seats.

    Perhaps the reason that the GOP House losses of seats were considered not so bad compared to 2006 was because in 2008 the Democrats ran up huge turnouts in black-represented Congressional districts, which were already all Democratic? That’s something you might look into.

  12. […] yesterday’s blog entry I looked that the swing in congressional voting nationally (House Democrats gained 5.7%, on […]

  13. Andrew says:

    Steve: Yes, this was part of the story. And, once the Republicans lost a bunch of these close seats, the incumbency advantage (about 8 percentage points, on average) automatically kicked in to make it easier for the Democrats to hold on to these seats. See recent blog entry for answer to your last question.

  14. dennisS says:

    Interesting stuff. I don’t get one point on the last graph. It seems to show Clinton getting better than 50% of the vote in ’92 and beating Obama’s mark this year. But, he didn’t. Did you just negate GOP shares, which isn’t really right during years with a significant 3rd party showing? Makes me question the whole graph or my understanding of what it portrays.

  15. Andrew says:

    Yes, it’s the Democratic share of the two-party vote; see the y-axis on the graph.

  16. dennisS says:

    Ok. I now see the distinction.

    I think you’ve made your overall point nicely, but your charts also reveal that over a 50 year span the public has favored a center-left Democratic congress and an authoritarian-leaning executive. More evidence that Obama’s achievement is pretty notable.

  17. […] polled better for Congress than for the Presidency but the areas where they over-performed were not distinctively southern, despite the media attention given to Democrats such as the anti-abortion gun enthusiast Bobby […]

  18. Gordon Linoff says:


    This analysis is very interesting, but it misses the point. As the saying goes “the proof of the pudding is in the eating” and the Democratics did worse than expected in picking up seats in Congress. This is all the more surprising, because the presidential polls were quite accurate, both overall and state-by-state.

    The analysis should be done by Congressional district, rather than by state. The logic is simple: the electoral votes for president (for the most part) are winner-take-all at the state level, so states are the important unit for analysis. Congressional seats are winner-take all at the district level, so districts are the corresponding important unit for analysis.

    If the additional votes for Democrats came in districts that are overwhelmingly Democratic, then the national vote totals change, but the impact on Congress is much less.

    Very interesting to me are the facts that there were 6.8M fewer votes for Democrats in House races than for Obama, and 8.4M fewer votes for Republicans than for McCain. Many people voted for the presidential candidates but did not support that party for Congress.

    These numbers are actually larger than in 2004, when the difference was about 6.3M for both parties. This suggests that Obama’s “coattails” were no stronger than Kerry’s (this is only a suggestion because we do not know the actual proportion of party splitting). However, McCain’s were considerably worse than Bush or Obama.


  19. Andrew says:


    As I noted in my P.P.S. above, I agree that seats are the relevant unit for evaluating political strategy and for considering policy implications of the election. But I think vote share is the relevant measure when studying public opinion, in particular in asking whether voters were trying to balance their Obama support with Republican voting for the House.

    I agree that the roll-off in downballot races is important; some comes in elections that are uncontested or not seriously contested. Beyond this, we know from polls that voters don’t generally have positive feelings about Congress in any case.

  20. Jeff says:

    I had a bet wish my sister-in-law. I bet that House Dems’ share of the nationwide vote would exceed Obama’s nationwide vote by more than 3%. Did I win or lose? I can’t find the data anywhere to the nearest decimal point. Help! A huge $20 is on the line …

  21. […] but they didn’t get as many seats as we would’ve expected, given their vote share. As I’ve already discussed, the Democrats’ 56% share of the average district vote was pretty impressive, a 5.7 […]

  22. […] meaning to write this up, but hadn’t had time to do the math. And now I don’t need to: Andrew Gelman is on the case. Here’s the key graph: A party […]

  23. […] Democrats did not do worse than they “should have” in the congressional races this […]