Democratic presidential candidate, Sen. Bernie Sanders. (Justin Wan/The Sioux City Journal via AP) (Justin Wan/AP)
Opinion writer

Scenes from an insurrection:

In Madison, Wis., on Wednesday, 10,000 people show up to rally for long-shot presidential candidate Bernie Sanders — giving the self-declared “democratic socialist” the largest crowd any candidate has had in this election cycle. Sanders, running on a shoestring and a prayer, has closed to within single digits of Hillary Clinton in New Hampshire and is surging in Iowa.

In New York on Tuesday, populist Mayor Bill de Blasio lashes out in vitriolic terms at New York Gov. Andrew Cuomo, a a fellow Democrat, accusing him of “games” and politically motivated “revenge.” De Blasio and other Democrats blast Cuomo’s handling of housing, immigration, the minimum wage and education.

In Washington last month, an overwhelming majority of Democrats — 158 of 186 in the House and 31 of 44 in the Senate — oppose President Obama on free-trade legislation. Obama prevails in the vote after failing in a similar vote earlier in the month, but the episode leaves the president attempting to repair a deep rift with his fellow Democrats by championing overtime rules favored by unions.

These are not isolated events. Together, they show anew how the populist movement is ascendant within the Democratic Party, and they confirm that the balance of power has shifted. Clinton, who reports raising $45 million since launching her campaign in April, will almost certainly beat the upstart 73-year-old with the crazy white hair. Obama won on trade. But Clinton and Obama are, to borrow a favorite phrase of the president, on the wrong side of history. As I’ve noted, the country is trending in a more liberal direction, and a growing proportion of Democrats are hard-core liberals.

There are various causes, but the change is likely in part a reaction to the tea party and to the Republican Party’s swing to the right. Democrats so far have shown less inclination to eat their own, but there is a real possibility that intraparty fratricide will break out if Clinton and the rest of the Democratic establishment don’t co-opt the rising populist movement. In New York, for example, there is already talk of a liberal primary challenge to Cuomo if he chooses to run again in 2018.

That the Sanders campaign has caught fire is a surprise to just about everybody, not least the candidate himself, who had his doubts. The Brooklyn-born Vermonter with a didactic style lacks the fire and charisma of Elizabeth Warren, who chose not to run. But his call for huge infrastructure spending and taxing the rich has caught the moment just right, even if Sanders himself is an imperfect vessel.

In May, Clinton had a 31-point lead in New Hampshire over her nearest potential Democratic competitor in the WMUR/CNN poll; now she leads Sanders by only eight points, which because of the poll’s methodology is a statistical tie. In Iowa, likewise, Clinton had a 45-point lead over Sanders in May, according to a Quinnipiac University poll. Now her lead has shrunk to 19 points.

The populist pushback that propels Sanders’s unexpected success also can be seen in the incendiary remarks of New York’s top populist, de Blasio, who took the extraordinary step of calling journalists to City Hall to denounce the governor. He called Cuomo’s actions “not anything like acceptable government practice,” according to the New York Times.

At the heart of the criticism is a sense that Cuomo, though the son of the late liberal lion Mario Cuomo, was insufficiently pure in his ideology and too willing to strike deals with Republicans. Several New York liberals have begun rumbles of a primary challenge to Cuomo — an effort that would be like the conservative efforts to purge the Republican Party of RINOs (Republicans in Name Only) in recent elections.

Obama, too, has been upended by the populist wave. Though he eventually prevailed in the “fast-track” trade vote, he had nothing like the support Bill Clinton got when he pushed through the North American Free Trade Agreement with half of Senate Democrats and 40 percent of House Democrats. Liberals called that a victory. “This isn’t 1993, and this is not Bill Clinton’s Democratic Party,” Rep. Rosa DeLauro (Conn.), who led Democratic opposition in the House, wrote in the Huffington Post on Thursday.

Bill Clinton reshaped the party with moderate “New Democrats,” but the new New Democrats look more like the old. Hillary Clinton, notably, sided with liberals on the trade legislation, which is smart: If she doesn’t want to get trampled by populists on the march, she’ll need to grab a baton and pretend to be the drum major.

Twitter: @Milbank

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