Lee Drutman in Vox:
There was a time, several decades ago, when America’s two-party system was praised for its moderation. Unlike European parliamentary democracies where “dogmatic ideological parties” of Europe thrived, America’s winner-take-all electoral system seemed to reward and therefore encourage parties and candidates with broad national appeal. No party, it was argued, could simply give up on half of the electorate. Similarly, no party could convincingly win a majority by putting forward extremist anti-system candidates far outside the mainstream.
Obviously something has gone wrong with this theory. Instead of being rejected as outside the mainstream, Donald Trump, an extremist anti-system candidate, simply redefined what “mainstream” is for almost half of the electorate.
And today, both American parties regularly forsake about half the electorate. Or even more than half, really.
Consider some basic numbers: Trump was the choice of 14 million people who voted in the Republican primaries. But in a nation where 230.6 million Americans are eligible to vote, that’s 6 percent of eligible voters. In the 2017 German election, the far-right populist Alternative for Germany (AfD) won 5.9 million votes. In a nation of 61.5 eligible voters, that’s almost 10 percent.
In short, when voters in both countries were given the full range of options, Donald Trump was less popular in the United States than the AfD was in Germany.
But in the German system, AfD can be kept out of power by other parties forming a coalition. In the United States, Trump’s 6 percent support gave him a major party’s nomination, which gave him instant legitimacy. And because he was a Republican candidate and because he wasn’t Hillary Clinton, 63 million Americans cast a vote for him — enough to catapult him to the presidency.
More here.