Does no-one remember how Hillary Clinton was the popular former Secretary of State with 60%+ approval, while Trump was the race-baiting laughingstock who would lose in a massive landslide if he were somehow nominated?
In another timeline, it may have been Sanders losing to Rubio after being successfully painted as a left-wing extremist, with the consensus being that the "Tea Party of the left" had cost the Democrats a probable win by rejecting the qualified establishment moderate in Hillary Clinton for "McGovern 2.0".
