The "left" in the United States is much further right on the global median. The Democrats are barely a center-left party on the global political spectrum.

Traditionally, at least since the Reagan Coalition was formed, the Democrats have functioned as a Republican-regulation party, the safety valve of rightwing ideas. The Republicans have put all of their chips on the Reagan Coalition, which they know is a tent with limited accommodations for the non-white non-rightwing. Both of these strategies have weaknesses that we can see cracking open in real time.

The Democrats, by comparison, are a much bigger tent of a party, and regional pressures and interests make it much harder for them to break the mold. There are still Democrats that identify as "conservative," if you can believe that, and a substantial amount of them, too. There used to be "liberal Republicans," but that number has dwindled into near-zero %.

I'm not in any way forgiving these dissenting senators for destroying what little health care Americans have. If there were any time in history where any one senator could choose to go rogue and still get re-elected, it's now.

You forgot:

-Centrists pretending they see through everyone by just picking the centerpoint on an arbitrary axis, without actually considering which side is actually correct