Crossover voters
There’s some talk about whether Democrats in Iowa have changed their party registration to vote in tonight’s caucus, specifically for Nikki Haley. The impact of this kind of crossover voting — especially in states where it’s relatively easy to do so — is probably one of those mythical things that political junkies really like to talk about, but doesn’t make much difference. For it to matter, a lot of people would have to cross over, or it would have to be a very close race between two candidates — or both. But if there have ever been perfect conditions for it, it’s this year, with not much of a primary race on the Democratic side and a lot of strong feelings among Democrats about the Republican frontrunner, Donald Trump.