The rest of the democrats watched as one of their own sacrificed themselves for the good of the herd. It's a good strategy to keep people like you thinking it's only the "bad apples" that ruin the party. The party can eject people who do not hold the party line, though, and they never do. There is always a rotating heel in the ranks, who defects at the final hour, so the rest of the party can shake their fists at them. When the lights go out, and they're all in the locker room, though, the party is glad they didn't need to show their full hand.

Popular public support for a given policy has no impact on its implementation. When changes are made through a truly democratic process, outside party lines, and not reliant on the party, the parties come together to dismantle it.