GWB won re-election via the "war on terror", which is the other sure fire way presidents get re-elected. You could even argue his dad
didn't win re-election despite being a good President, due to withdrawing from the Middle East (which, IMO, was the right thing to do).
As far as effectiveness or even shooting themselves in the foot, I don't disagree. But, again, that's not what we're talking about.
A guy like Manchin does give the Democratic party a bad name, but it's also patently clear he's in the minority there.