I urge everyone to read John Sides over at the Monkey Cage on elections and the economy. He's responding to David Paul Kuhn, at Real Clear Politics, who has a piece claiming to debunk what he calls "economic fatalism."
First, I think this is a very healthy debate to be having. To the extent that people are looking, generally, at systematic reasons that elections turn out as they do -- and what is left to explain beyond that -- everyone is better off. I think Kuhn underestimates the extent to which it's a major achievement to have the Washington Post publish an article devoted to the evidence on that sort of thing. If Ezra Klein oversimplified things in his piece, or if there's more debate than he let on, by all means it's a good thing to take issue with it. But make no mistake; what Klein produced is far, far ahead of what John cites -- the awful NYT op-ed page "How to Fix Obama" feature from this past Sunday.
So, yes, the economy isn't the only thing that matters in elections. In presidential elections, it turns out that it's not really a good idea to subject your nation to an endless, high-casualty war, especially one that you're not winning. There's also evidence that there's a general reaction against keeping the same party in office indefinitely, so it's a plus if your party his been out of the White House for three or more terms. And, yes, it's not a good idea to select someone far from the ideological mainstream -- that's really only mattered significantly with Goldwater and McGovern (and even then, only to the margin of defeat), but it probably has made a bit of difference in other elections. In Congressional elections, candidates matter to some extent. Open seats are more difficult to defend, so an incumbent party hit with a wave of retirements will tend to be hurt in November. Challenger quality matters, so a party that does a good job of recruiting a solid crop of candidates (as the Democrats did in 1974 or the GOP in 1994) will be better off than one that doesn't (such as the Dems in 2002).
In other words, yes, there are systematic things that matter in elections in addition to the economy. The point is that when we talk about elections (or, perhaps, presidential popularity) to look to those things first.
Beyond them? Yes, there's also some margin of error, so we can try to explain that by factors specific to particular elections. The complaint of the political scientists is that this should be done, and usually isn't done, in the context of the systematic factors. So, yes, perhaps if Barack Obama gave a few more better speeches about better subjects he might have nudged his approval ratings up a point or two. But the overall context of those approval ratings is going to be the big, systematic factors. And, in fact, Obama is basically more or less where one would expect given those factors. Similarly, the Democrats should expect to lose seats this November because of the big, systematic factors -- the biggest and most obvious of which is just that they've done so well in the House recently that they're defending lots of marginal seats, and have very few marginal seat targets.
There's a very strong, and really understandable, urge for us to believe that the day-to-day stuff matters to election outcomes: the gaffes, the debates, the ads, the strong speeches, the policy proposals. And sometimes they do! Mostly, though, they don't, or they matter just on the margins. As I've said many times, that doesn't mean that the ephemera of campaigns shouldn't be reported (and it may in fact be important to what pols do once they're elected, even if it doesn't sway voters). It just should be reported in context. Yes, I'm repeating myself, but it's for emphasis: marginal things should be reported as if they were marginal things, which requires keeping the context in the forefront. Or, reporters can simply avoid claiming or implying important effects for things that are unlikely to have such effects. In other words, I understand that it's impractical for reporters to constantly include reminders that really the economy and other systematic factors matter much more than X; that's not necessary if reporters would stop making claims about how X is likely to affect election results.
At any rate, what's terrific about Ezra Klein's piece is that it provides that a large piece of that context, in a clear and readable way, in a major newspaper.