Much has been written about the Democrats’ question in this election: whether ideological purity is the best way to beat Donald Trump at the ballot box. The party must decide whether to race economically and culturally leftward or to remain stubbornly anchored to the center ground.

The Green New Deal is a clear example of the former. It calls for a top-to-bottom renovation of the U.S. economy in order to address man-made climate change. It’s a set of vague, infeasible, partisan aspirations that package up substantial economic reform in a sparkly green box.

Almost every Democratic presidential candidate was quick to endorse the policy, but it was met by skepticism by those within the party who are concerned that a leftward tilt will only aid the Republicans.

And in sunny California, their fears are being proven right. This week, union workers in Los Angeles are planning a massive “Blue Collar Revolution” demonstration at the Democratic Party Convention. Their message: We do not want our jobs to be put up for sale.

The move should act as a cautionary tale to any Democrat who has assumed that the party’s base will follow it like lemmings. People vote on the basis of their immediate interests, as well as their morals — climate-change policies will only win if they address both.