Iowa, New Hampshire and South Carolina are losing their clout, some current thinking goes, because new campaign-finance rules (or you could say lack of rules) will allow more candidates to last longer in the nomination process.

Here's how the Wall Street Journal's Patrick O'Connor puts it:


"The candidate field looks unusually crowded, with more than a dozen contenders appealing to different slices of the GOP. The rise of super PACs allows candidates to stay in the race longer than before. And nominating rules meant to compress the process may complicate a front-runner's ability to amass the delegates necessary to win."

But political scientist Josh Putnam, the expert on the schedule of caucuses and primaries, knocks down that theory at his FHQ blog.

If Iowa, New Hampshire and South Carolina don't matter as much, he asks, then why are the candidates spending all their time so far in Iowa, New Hampshire and South Carolina, exactly as presidential contenders have done for decades? If states with March primaries are now the most important ones, no presidential politician so far has figured it out.

It's always possible that something has changed, Putnam says -- something that politicians and political scientists have missed.

But he sees nothing in the rules, the schedule or the money part that will save any candidate who doesn't come out of Iowa with at least a respectable showing, or who can't show some serious strength in New Hampshire and South Carolina. Neither do I.

Money may be plentiful, but there's no evidence donors are going to suddenly decide to stick with a losing candidate, just because the law allows them to. Nor are there any signs that candidates who have lost all reasonable hope are going to be more likely to stick around for humiliation after humiliation on the off chance lightning will strike.

Winnowing works.

And the winnowing is happening earlier and earlier. The primaries and caucuses in general have lost clout to party actors who make their choices before voters get involved at all. Republicans have been especially efficient at narrowing their field well before the Iowa caucuses.

So don't expect all the candidates who will be announcing their formal campaigns in the next month or so to be around in January 2016, when the first votes come in. And it's unlikely that more than two or three real potential nominees will still be contesting their party's nomination after South Carolina, even if a few no-chancers stick around to keep it entertaining, as Newt Gingrich and Rick Santorum did in 2012.

If the last two standing turn out to be evenly matched, as Barack Obama and Hillary Clinton were in 2008, then it's possible we will see a real marathon.

More likely, however, is a knockout blow before Iowa or in one of the first three states.

Jonathan Bernstein is a Bloomberg View columnist covering U.S. politics.