This afternoon, Chris Christie endorsed Mitt Romney for president. Political junkies are agog over the news. But what do political scientists think? Here’s an old interview with Georgetown’s Hans Noel, who co-wrote “The Party Decides: Presidential Nominations Before and After Reform.” He argues that insider endorsements like Christie’s can prove quite significant:

When endorsements start to converge, voters can sense that most of or all of the party is for a particular candidate. For the most part, people who are voting in the primaries are partisan, and they listen to that party signal. We show in the book that the relationship between who has the most endorsements and who does well is strongest among partisan voters. Independent voters don’t pay much attention, but then independent voters are a smaller share of the primary electorate.

But probably the biggest way in which endorsements matter is that they’re a way for us to observe the support that’s going on behind the scenes. If the governor of a state says I’m for this candidate, it might also mean he’s going to give some advice and say in my state, these are some things you want to know. Or his staff, or people who have campaigned for him, are going to be willing to campaign for the candidate. When you show up in South Carolina to build a campaign, there are only so many people who you want to hire who know how to do that. So those people are going to have a choice of which candidate they want to run with, and they might choose the candidate who their governor supported.

I should add, we spend a lot of time in the book talking about who has the most endorsements. But the argument isn’t that whoever has the most endorsements wins. It’s that whoever the party is supporting wins, and endorsements are one way of getting at that.

There’s a lot more of interest in the rest of Noel’s interview with Columbia Journalism Review’s Greg Marx.