Could someone like Ted Cruz get elected president? I wrote a bit about this subject last week at Mischiefs of Faction but wanted to elaborate a bit here. The quick version is that getting a major party's presidential nomination is an extremely high hurdle. But anyone who gets it has a decent chance of becoming president, no matter who they are or what they believe.
A great deal of political science research focusing on American presidential elections has found that only a very small number of factors actually make much of a difference in the election outcome. The big one is economic growth. If the economy is growing, people tend to reward the party in power with another term in office. Another factor is war: If many American soldiers are dying abroad in an unpopular war, people tend to blame the party in control of the White House. (Douglass Hibbs' "bread and peace" model summarizes this nicely.)
A great deal of political science research focusing on American presidential elections has found that only a very small number of factors actually make much of a difference in the election outcome.
A great many other factors—including ones that the campaigns devote a tremendous amount of time and effort to managing—turn out not to really affect the way people vote. That includes things like candidate personality, sex scandals, debate performances, speaking ability, campaign slogans, theme songs, and so forth. It's harder (though not impossible) to measure things like the impact of campaign advertisements, since both campaigns tend to do those simultaneously, but if you look at places where one campaign outspends the other or advertises where the other is silent, you can find modest advertising effects. But those effects tend to be small and, more importantly, fleeting.
Candidate ideology is a tricky one. Some literature suggests that more ideologically extreme or partisan candidates tend to have a harder time winning election. And it's quite possible that extremism has hurt some presidential candidates. To get a sense of this, look at the scatterplot below, showing the relationship between economic growth (measured as real disposable income growth in the year prior to the presidential election) and the vote share for the incumbent party's presidential candidate:
The economy is a pretty strong predictor of results. But some candidates appear well above or below the trend line. Lyndon Johnson in 1964 and Richard Nixon in 1972, for example, share the distinctions of being widely perceived as moderates (at the time of the election) who had the good fortune* of running against people who were widely perceived to be extremists: Barry Goldwater and George McGovern, respectively.
Those presidential elections have probably the greatest disparity between candidates' ideological reputations. And as the chart above shows, Nixon and LBJ both over-performed the economy. That is, they got more votes than we'd expect them to get from economic growth alone. The economy was in pretty good condition in 1972 and in amazing shape in 1964, so these presidents would likely have been re-elected even if they'd run against better candidates, but we can still see some effect of extremism.
So there's an extremism effect, but it's usually trumped by the economy and war. What's more, the extremism effect we see in the Nixon and LBJ races occurred at a time when voter loyalty to the parties was about as weak as we've seen in modern American politics. There were, say, conservative union members who saw themselves as Democrats but couldn't bring themselves to vote for McGovern, whom they saw as a socialist. There were, say, moderate businesspeople who thought of themselves as Republicans in 1964 but were terrified of Goldwater and actually voted Democratic as a result.
That really wouldn't happen today, at least in those kinds of numbers. Voter partisan loyalty is much stronger now. Remember, Mitt Romney got 78 percent of the white evangelical Christian vote in 2012—the same percentage George W. Bush got in 2004—despite the fact that many evangelical Christians viewed Romney, a Mormon, as un-Christian at best. Regardless of who the next candidates are, Democrats will vote overwhelmingly for the Democrat and Republicans will vote overwhelmingly for the Republican. Even a pretty extreme Republican (and I think it's fair to refer to Cruz that way) would have a good shot against presumed Democratic nominee Hillary Clinton (who would probably not be perceived as quite as moderate as Nixon or LBJ anyway).
This is one reason why the presidential nomination process we're in the middle of right now is so important. The parties themselves are doing a great deal of selection on behalf of the rest of us. They're the ones who keep crazy people from getting nominated, not necessarily because they don't think a crazy person could win—he or she totally could—but because parties actually want to get something out of controlling the White House and you really don't know what you're getting when you select a crazy person to represent you.
*OK, Nixon's match-up against McGovern wasn't entirely due to good fortune. Nixon's infamous dirty tricks operation helped knock Edmund Muskie out of the race, and he likely would have been a much stronger candidate than McGovern. John Dickerson provides a great rundown of this at the Whistlestop podcast.
What Makes Us Politic? is Seth Masket’s weekly column on politics and policy.