I think a lot of them are pros, who go where the going is good.
Look at Dick Morris, former Clinton advisor, now a fixture on conservative talk shows.
Republican campaign workers have been playing Musical Candidates during the primaries. Of course, that's mostly the same ideology, but still.
Watch for the people who stick with someone even when the chips are down.
And yeah, no major names in politics come immediately to mind.
It's not like any of this stuff is new. Check out the 1884 election.