Two years after Alexandria Ocasio-Cortez toppled a congressional power broker and challenged New York’s political conventions, the far-left movement that boosted her to the national stage has demonstrated it is here to stay.

Now, after turning away sitting politicians in Congress and Albany, the latest iteration of the movement will face its first citywide test.

New Yorkers will elect a new mayor in 2021, when term limits force out Bill de Blasio. The race provides a chance for the most liberal wing of the Democratic Party to seize its biggest electoral prize yet — one of the most prominent political jobs in America at a moment of unrivaled turmoil. The next mayor, almost certain to be a Democrat given the party’s 7-1 registration advantage in the city, will at once contend with a national call for police reform and the fallout from Covid-19, which has frozen tourism and decimated an economy that was booming only six months ago.