Political scientists have devoted vastly more attention to general presidential elections than to party nominations for president. This emphasis might be reasonable if parties could be counted on to nominate generic representatives of their traditions. But it is clear that they cannot. Since the party reforms of the 1970s, regulars like Bill Clinton, Bob Dole, and Al Gore have sometimes won fairly easy nominations, but outsider candidates like Jimmy Carter and Howard Dean have made strong runs or even won. 2016 has produced extremes of both types: ultimate regular Hillary Clinton on the Democratic side and far outsider Donald Trump on the Republican side. It seems, moreover, that party regulars are having more difficulty in recent cycles than they did in the 1980s and 1990s. There is therefore some urgency to the question: when and why do party regulars tend to win nominations?

We examine this question from the point of view of two well-known studies, Nelson Polsby’s Consequences of Party Reform and our own, The Party Decides. The former explains why incentives built into the reformed system of presidential nominations make outsider and factional candidates like Trump likely. The latter argues that, following the factional nominations of the 1970s, party leaders learned to steer nominations to insider favorites. This article uses the logic of these studies to argue that major trends over the past two decades – the rise of new political media, the flood of early money into presidential nominations, and the conflict among party factions – have made it easier for factional candidates and outsiders to challenge elite control of nominations.