But if Trump had begun his administration by seeking a bipartisan infrastructure bill, Schumer would have had no choice but to cooperate, and might well have welcomed the chance. Half the unions that normally support Democrats would have been on Trump’s side and pressing both parties to get on board.

Instead, Trump opened his presidency with a dark and one-sided address that gave no credit to his predecessor and opened no doors to cooperation. He followed that address with bizarre misstatements about crowd size and tweets mocking the protesters who marched in vast numbers the next day. “Why didn’t these people vote?” Trump taunted.

“These people” were Schumer’s base. Only days into the administration, thousands of liberals were demonstrating outside the Brooklyn apartment building where the senator lives. “Grow a spine, Chuck!” they demanded. “Filibuster everything!”

Even then, you might have made a case that for the good of his party, and the country, Schumer should stand up to his left wing. But he would have had to make common cause with a president who was belittling him as “head clown” and “Fake Tears Chuck Schumer.”