20 years ago it was certainly also the case that The Powers That Be in the Democratic party tended to try to push things to the center, and leftier members tended not to be the most popular ones in the building, but I don't remember people freaking out over a few lefty House members and the occasional Senator, either.
There was resistance, but not enraged panic. James Carville didn't throw a hissy fit every time someone to the left won a primary. It's very strange.
