21 January 2010
Political scientists David Brady and Doug Rivers, along with business and law professor Daniel Kessler wrote an op-ed for the WSJ arguing that the health care bill is hurting the Democrats. Their evidence is that states with lower support for the bill also have lower support for incumbent Democratic senatorial candidates:
Health reform is more popular in some of these states than in others. Where it's popular, Democratic candidates don't have too much of a problem, but where it's unpopular--and that includes most states--the Democratic Senate candidates are fighting an uphill battle. Support for health reform varies in these 11 states from a low of 33% in North Dakota to a high of 48% in Nevada. Democrats trail Republicans in six of the states; three are toss-ups; and in two, Democrats have a solid lead.I hate to fill any kind of institutional stereotype, but the causal reasoning here leaves much to be desired. The argument of the essay is that BECAUSE of health care, Democrats are doing worse in the polls. On this question, obviously, we have no data: this is why speculation is running rampant. The counterfactual would be: what would have happened to Democratic senatorial candidates if there had been no (or a substantially smaller) health care bill? Pundits can hardly type fast enough to get answers to this question out right now. Certainly, though, a correlation of support for health-care and support for Democrats will not provide the answer (since, you know, there is no variation on the treatment--all states are in the health care reform world).
Despite the general tone of the piece ("The culprit is the unpopularity of health reform...") , I believe the authors are making a different argument. Namely, that voters are responding to their senator's vote on health care. Based on their evidence, however, I think this is a flawed argument as well.
Confounding is an obvious problem here. There are many factors that could influence opinions on health care and the Democrats (ideology, economic performance, etc). The authors clearly consider possible problems of confounding:
How do we know that it's the health-reform bill that's to blame for the low poll numbers for Democratic Senate candidates and not just that these are more conservative states?
First, we asked voters how their incumbent senator voted on the health-care bill that passed on Christmas Eve. About two-thirds answered correctly. Even now, long before Senate campaigns have intensified, voters know where the candidates stand on health care. And second, we asked voters about their preference for Democrat versus Republican candidates in a generic House race. As in the Senate, the higher the level of opposition to health reform, the greater the likelihood that the state's voters supported Republicans.
It might be the case that voters are punishing known health care supporters! But, again, I am not sure that these polls show this. The Senate vote was party-line. If someone knew their senator's party, then they could infer their vote without actually knowing it. They could simply know that Democrats are trying to reform health care and their senator is a Democrat. Under this scenario, the actual vote of the senator would make not difference since our hypothetical voter equates Democrats with health care reform.
Put it this way: do you think that House Democrats that voted against the bill are going to have easy reelection campaigns? That seems like the real test of this hypothesis.
A simple gut check would be to run the same analysis with the stimulus instead of health care. I imagine you would get similar results. The point is that the advice from this article for Democrats--withdraw support for health care reform--is not supported by the data.
UPDATE: Brendan Nyhan over at Pollster makes essentially the same argument.
Posted by Matt Blackwell at January 21, 2010 4:02 PM