I’ve been saying that the Supreme Court decision on the Affordable Care Act won’t have much of an effect, if any, on the elections in November. Seth Masket has the same conclusion:

But in the end, sentiments about health reform are already baked into people's assessments of the candidates. People know that Obama supports it and that Romney (for all his history) opposes it, and nothing that happened yesterday changes that. Perhaps Roberts' conservative apostasy may cause a few people to reassess ACA (although see here), but my guess is that it mainly causes people to reassess Roberts.

Note that Seth has a hint in there about why it feels to so many of us that yesterday’s ruling should, somehow, matter in November. Not just that, either — it feels as if the candidates’ styles and personalities should make a difference, and that issues should matter, and generally that lots of things that political scientists will tell you are insignificant really feel as if they’re determining votes.

I think there’s two parts to it, really. One is that our reactions to most campaign events — the ads, the gaffes, the debates — are filtered through our partisanship. If you’re a Republican, you are very, very likely to think of Mitt Romney as a serious just-get-it-done businessman whose personality is perfect for tough economic times; if you’re a Democrat, you’ll find him a condescending, uncaring, automaton. Republicans thought “doing fine” was a revealing gaffe; Democrats thought “Etch-a-Sketch” was.

The second part is that all those issues that we feel passionately about are, in most cases, what makes us Democrats or Republicans to begin with. But for electoral analysis, I don’t need to know whether you’re a Democrat because you care about marriage equality, or because your parents were Democrats, or because you’re in a highly Democratic group such as young single women. All that I need to know is that you’re a Democrat, and I can predict with very high accuracy that you’ll be voting for Barack Obama. Yet that’s from the outside. From the inside, Democrats struggle (for example) with three plus years of the president, sometimes (health care passes, DADT repeal) excited about him and sometimes (public option dropped, casualties in Afghanistan) exasperated. And those are very real reactions to what’s going on; I don’t mean to dismiss them. They just don’t have much to do with a decision in November 2012 of whether to vote for Barack Obama (and all he stands for) or Mitt Romney (and all he stands for).

Indeed, if you talk to even serious activists, you’ll find that they deviated from their party all the time on this issue or that, or this evaluation or that. The big-picture statistical look at it misses all of that – and to us as individual citizens, those deviations can be just as important and certainly are just as real as the stuff that the statistics pick up on. And because all of that is going on, it feels very much as if the day-to-day events of the campaign are probably important to the outcome. It’s only when we back up to that quantitative view that we realize that, no, most of the time they really don’t.