I listened to bogus excuses like this for decades.

This is not a new problem. The idea of a party whip has been around for centuries. "If you vote for this, we'll give you this perk. If you don't, we'll destroy your career and we'll hire detectives to find out who's bribing you and every other embarrassing fact about you."

However, the Democrats would rather lose their battles than lose their imaginary moral high-ground.

"Well, America collapsed, and we did nothing, but we had the moral high-ground, so it's a win for us!"