Political scientist Brendan Nyhan makes an important point about the presidential election: There’s an excellent chance that none of what’s happening in the campaign matters. At all:

As a result of these pre-existing views and the passage of time, most of the messages that voters are receiving now about Romney will wash out over time. Research by the political scientists Christopher Wlezien and Robert Erikson on trial heat polls finds that pre-convention “news about the campaign affects voters but is eventually forgotten and thus has little impact on the final outcome.”…And even if those messages do have a lasting effect on perceptions of Romney, the political scientist Larry Bartels has found that presidential “candidates’ images are largely epiphenomenal and have only a modest impact on election outcomes”—i.e., their images are more a consequence than a cause of how the candidates are faring.

Now, what’s happening to the nation, especially the economy, certainly matters. But electioneering — everything from early ads, to mini-controversies on the Sunday shows or Twitter, to the candidates’ speeches — probably don’t. They will matter a bit in October, yes. But even the relatively small group who are paying attention now — most of whom are strong partisans anyways and therefore aren’t up for grabs — will probably forget whatever it is that “everybody” is talking about now.

One thing worth remembering about this is that the current campaign period, in which both major parties have chosen their candidates and have tons of money to spend, is a very new phenomenon. Before party reforms of 1968-1972, nominees were not selected until the conventions; even many incumbent presidents were not quite certain to be renominated. Think back twelve months to the silly season speculation that Barack Obama would be challenged in the primaries; before 1972, that speculation would go on up to the convention, because much of the real action was there.

Beginning in 1972, most nominees emerged earlier, and almost always by early June. In the 1970s and 1980s, however, campaign finance regulation meant that they didn’t have a whole lot of excess money to spend. There’s a bit more to it: in 1972 the Democrats didn’t have a clear nominee before the convention, so Richard Nixon couldn’t simply attack the likely nominee (who he wanted to get the nomination, after all). In 1976 the incumbent Republicans didn’t have a nominee until the convention; same for the incumbent Democrats in 1980. So spring attack ads by the incumbent against the out-party nominee weren’t really practical in any of those cycles.

So in 1996, when Bill Clinton spent the spring “defining” Bob Dole, it was actually a fairly innovative thing, and since Clinton won, everyone assumed it must have worked. As Nyhan points out, however, Clinton mainly won because of peace and prosperity, not because of campaign-level stuff. (Indeed, it’s not at all clear that Clinton overperformed the economy.)

That example is probably the biggest reason that everyone makes a fuss about winning news cycles in May and June. The other reason is that it’s in the interest of a lot of people – the press, because they need something to talk about and campaigns are easy and popular, and the campaigns, which need to justify their own importance.

All of that, however, doesn’t change the basic fact that what happens now in the presidential campaign probably doesn’t really matter much.