Bush’s overall policy positions look like those of previous GOP nominees over the past 50 years. In an analysis of different ideological rating systems by FiveThirtyEight editor-in-chief Nate Silver, Bush’s ideology was similar on a left-right scale to Romney’s and John McCain’s.

Voters who support less extreme candidates can still swing Republican nominations, according to Henry Olsen of the Ethics and Public Policy Center, a conservative advocacy group. (Just ask Romney and McCain.) And even very conservative Republicans are concerned about winning the White House: The ability to defeat Obama was the No. 1 most important quality for a candidate in 2012. The GOP insiders that Rucker and Costa cite have deemed Bush an electable candidate (for now).

2016 could be different if the tea party has its way. But — as “The Party Decides” found — the longer a party has been out of the White House, the more it tends to nominate more moderate candidates. That’s not to say that potential nominees won’t try to placate the tea party, or religious conservatives like those who voted for Santorum. But such groups’ influence could be lessened as Republicans contemplate 12 or 16 years without one of their own in the White House.