But Democrats considering this sales pitch should be very clear on what a Bloomberg presidency would mean. Bloomberg does not have Trump’s flagrant vices (though some of his alleged behavior with women is pretty bad) or his bald disdain for norms and rules and legal niceties, and so a Bloomberg presidency will feel less institutionally threatening, less constitutionally perilous, than the ongoing wildness of the Trump era — in addition to delivering at least some of the policy changes that liberals and Democrats desire.

However, feelings can be deceiving. Trump’s authoritarian tendencies are naked on his Twitter feed, but Bloomberg’s imperial instincts, his indifference to limits on his power, are a conspicuous feature of his career. Trump jokes about running for a third term; Bloomberg actually managed it, bulldozing through the necessary legal changes. Trump tries to bully the F.B.I. and undermine civil liberties; Bloomberg ran New York as a miniature surveillance state. Trump has cowed the Republican Party with celebrity and bombast; Bloomberg has spent his political career buying organizations and politicians that might otherwise impede him. Trump blusters and bullies the press; Bloomberg literally owns a major media organization. Trump has Putin envy; Bloomberg hearts Xi Jinping.

In our era of congressional abdication, all presidents are prodded or tempted toward power grabs and caesarism. But Bloomberg’s career, no less than Trump’s, suggest that as president this would be less a temptation than a default approach.