A movement firmly committed to bringing about the scale of changes Sanders has been advocating wouldn’t hesitate to “heighten the contradictions” — that is, allow things to get worse in the short term (by acting in a way that helps Trump to win a second term) in the hope that better long-term prospects for progress (namely, a big shift to the left in the electorate) would emerge from the mess. If nothing else, a second loss to Trump would ensure the overthrow of the establishment that has led the Democratic Party since 1992, thereby opening up the prospect of its takeover by left-wing populists by 2024.

As I’ve pointed out before, the Democratic electoral coalition is extremely broad, and perhaps too broad for its own good. A party that’s big enough to include everyone from socialist Bernie Sanders to liberal Republican Michael Bloomberg is a party that will struggle to find a single standard-bearer who can unite its disparate factions. It might even be a party poised to shatter into its constituent parts.

The Sanders campaign may well end up being the catalyst that prompts the detonation.