In a recent opinion piece, The New York Times' Michael Lind asserts that the 2016 presidential election portends a political near-future in which the ideologies of Hillary Clinton and Donald Trump become the main platforms of the Democratic and Republican parties, respectively.
While Lind makes insightful and important observations into the history of each party, his assertion is just that: an uncertain prediction of what the future holds. It is based on the popular vote of what ultimately amounts to a minority of voting-age Americans, and discounts other significant factions of each party. This thinking also assumes that other voters will simply line up behind Clinton and Trump -- such as Vermont Sen. Bernie Sanders' supporters and those of Texas Sen. Ted Cruz.
Let's just take a look at the numbers first. Roughly 8 million Americans have cast a primary vote for Donald Trump so far, and a bit less than 9.5 million have voted for Hillary Clinton. How many Americans voted in 2012? About 129 million. Of course, if Trump and Clinton are the nominees then their support within their respective parties will obviously increase -- or at least increase somewhat, in Trump's case -- but this increase does not prove that the ideas which both candidates have been stumping on the campaign trail amount to the future dominant ideologies of each party.
The American political system has more or less always been dominated by two main parties: Federalists vs. Democratic-Republicans, Whigs vs. Democrats, Republicans vs. Democrats. Unlike European parliamentary parties, which can often be driven by ideology, American political parties have historically been driven by the need to represent different groups with differing ideologies. Hence, labor unions, southern whites and African-Americans formed the backbone of the Democratic Party following the passage of the New Deal, while the Republicans were largely supported by coastal elites and middle-class Midwesterners.
Lind does not give enough attention to this feature of America's party system in his discussion, and negates the agency of Bernie Sanders' and Ted Cruz's supporters, who respectively represent pointed challenges to their party's front-runners.
Sanders appeals to Democrats who feel that Hillary Clinton is untrustworthy and likely to cave under pressure to the demands of large corporations, and to sign legislation like the Trans-Pacific Partnership. Cruz's supporters appreciate the candidate's honest belief in conservatism and limited government and see Trump as nothing more than a saboteur to the conservative movement. Much as Trump and Clinton wish these factions of their parties would simply go away or shift their support, ideology does matter for a lot of people.
And as far as the Republicans go, I have not even mentioned the "establishment" which despises both Trump and Cruz. Lind believes that Trumpism will assert enough power within the Republican Party that the GOP will need to move sharply to the right on immigration and leftward on entitlements to appease the voters. This is certainly possible, but it is also possible that the "establishment" wing and the Ted Cruz camp find common ground on their hatred for Trump and his supposedly "left-wing" economic ideas, which would represent another powerful current within the party.
Four years is an eternity in political time, and it is possible that the populist upswell this election season dies out before this time next year. But it is impossible to tell which ideologies are going to emerge dominant within each party because each party is currently slugging it out. A minority of Americans have voted for Clinton and Trump so far, which is certainly no indication of ideological capture by either.