Either timid or threatened with blackmail or worse.
If they keep their mouths shut and go along with the party line of capitulation to Democrats, they have a fat pension, book deals, accolades, awards, a sinecure, consulting fees, etc., awaiting them when they leave office.
If they go against the Democrats, they may have their professional and personal lives destroyed.
And they know it.
Yep, their motivation is cashing in, not making this a better country.
Hope they enjoy their phony lives.