The Democratic contenders for their party’s presidential nomination are offering the most radical policy positions since the failed presidential campaign of Sen. George McGovern (D-SD) in 1972.

From the “Green New Deal” — a socialist policy nearly every Democratic presidential candidate now supports — to “Medicare for All” and even reparations for slavery, Democrats are proposing extremist ideas that enjoy almost no support from the American electorate as a whole.

Republicans who are nervous about 2020, given the constant assault on President Donald Trump by the media and the opposition, are cheered by the Democrats’ rush to the far-left. Some note the rise of energetic, social-media-savvy “democratic socialists,” such as Rep. Alexandria Ocasio-Cortez (D-NY). Some credit the influence of Trump himself, whose success in disrupting conventional politics has encouraged Democrats to be their authentic selves.

But the real reason Democrats have become so radical may be that Trump has effectively seized the middle ground of American politics. While governing as the most conservative president since Ronald Reagan — given his judicial appointments, his staunch pro-life policies, and his rollback of the administrative state, among other policies — Trump has made his toughest political stands in favor of common-sense positions that are broadly supported by the public.

Take, for example, his fight for the border wall. Though we are often told that Americans want to offer illegal aliens a “path to citizenship,” the overwhelming majority also wants to secure the border first, so that any amnesty offered will be the last. A recent poll showed a majority of Americans preferred a border wall to the Green New Deal. Few Americans want open borders, which is the de facto position of the Democratic Party and most of its candidates.

Likewise with Trump’s stand on trade. The free-trade consensus in Washington, DC, has long been at odds with the consensus in the rest of the country, which likes the benefits of free trade but also wants the government to fight for fairness in international commerce. Thus far, Trump’s trade war with China has hurt a few industries — most notably agriculture — but the anticipated price increases have not appeared. His position is simply seen as common sense.

Few Democrats want to be seen supporting Trump. But given Trump’s ostentatious support for middle-of-the-road policies — including preserving Medicare and Social Security — the only way for them to create “clear blue water” between themselves and the incumbent has been to offer the electorate eccentric socialist dogma. Despite their contempt for Trump, he has maneuvered them into a political position from which it will be very difficult to win.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.