Many Americans view the Democratic and Republican parties as mirror images of each other. This kind of Tweedledee and Tweedledum symmetrical perspective serves to mask important differences between them, differences which may help explain why the number of GOP candidates for president in 2016 is three times the number of Democratic candidates. There are always more candidates with no incumbent running, and Hillary Clinton is viewed as having the inside track to the Democratic nomination thereby blunting the emergence of additional challengers to her. But these two factors alone do not fully account for the lopsided number of candidates. Something else is going on here and new research points to the asymmetry of the two parties themselves as an additional explanation.
Historically, those studying American party politics viewed the two parties as being controlled mostly by their respective elected politicians who used the organizations as vehicles for their own ambitions and goals. Within the last decade this view has given way to a more nuanced one of parties as extended networks of interests, with elected officials being only one part of those networks, and not necessarily the most powerful component. The significant factors contributing to this evolution are the enlarged role of campaign finance, the Tea Party movement, and a public that favors liberal positions on policy issues but conservative ideas of smaller government. As a result, the parties have become much more asymmetrical. While the Democratic Party has largely remained a loose constellation of social groups seeking concrete government action, the Republican Party has morphed into a vehicle for a movement whose followers primarily cherish ideological purity.
Supporting this newer interpretation, scholars Matt Grossman and David Hopkins report national survey data showing Republican respondents conceptualize political parties in ideological ways whereas Democrat respondents tend to articulate party politics in terms of group benefits. When strength of partisanship is measured, strong Republicans are 40% more likely than strong Democrats to express an ideological conception, as opposed to a group-benefits view, of their party. Finally, about 60% of Republican respondents claim to prefer politicians “who stick to their principles” compared to only 40% of Democrat respondents.
How might this evolution of the parties help explain the large difference between them in numbers of presidential candidates? Democratic candidates for president face the task of appealing to as many groups as possible without the need to demonstrate significant ideological purity. Democratic voters are content with candidates who seem willing to compromise in an effort to meet the needs of many groups. On the other hand, a Republican candidate must demonstrate he or she is the only true conservative in order to gain traction among the base, and since purity is an exclusive characteristic, it allows, even requires, more candidates to step forward to make that claim. This insistence on purity makes it difficult for new-age Republicans to negotiate within their own ranks, and when elected, it constrains their ability to govern since bargaining and compromise are at the heart of our democratic process.