Are Trump supporters really anything new when it comes to general elections? Photo: Sean Rayford/Getty Images

If you want to make a case that Donald Trump can win the presidency in November without huge “black swan” events like another 9/11 or Great Recession, and you don’t buy dumb polls suggesting Trump’s actually very popular among Latinos, then you are driven to one of two intersecting theories. The first is the famous “missing white voters” hypothesis, which suggests that Mitt Romney left millions of votes on the table in 2012, and Trump’s just the guy to bring these voters to the polls. And the second is the theory beloved of some Democratic lefties that as a “populist” Trump’s going to win former Democratic, white, working-class voters alienated by Hillary Clinton’s Wall Street ties.

Politico has, however, done some number-crunching from the GOP primaries and concluded (tentatively, at least) that Trump’s base of support backs neither of the theories of an expanding GOP:

While Trump’s insurgent candidacy has spurred record-setting Republican primary turnout in state after state, the early statistics show that the vast majority of those voters aren’t actually new to voting or to the Republican Party, but rather they are reliable past voters in general elections. They are only casting ballots in a Republican primary for the first time.

If that’s true, then what the Trump candidacy represents is not some realigning event that could change our understanding of the general-election landscape, but simply an intra-party coup that overthrew the dominance of the business-as-usual and conservative-movement Establishments without necessarily adding to the total number of people prepared to vote Republican in November.

Now even if you don’t believe Trump is God’s gift to Democratic GOTV efforts, it’s pretty safe to say he places a cap on the GOP share of minority voters. So at best the general-election polls showing a tightening Trump-Clinton race may be about as good as it gets for the mogul, showing that he’s consolidating the same old GOP vote without materially adding to it.

On the other hand, the Politico analysis could be wrong. But it helps expose the tenuous reasoning behind Trump-can-win scenarios that rely on hoary ideas about hidden majorities and transpartisan “populist” winds that blow up the existing party coalitions. If the typical Trump supporter is someone who has voted for GOP presidential candidates monotonously since the Reagan Administration without necessarily buying into the party’s economic orthodoxy, then that should be terrifying to the U.S. Chamber of Commerce, but not so much to Democrats.

