“He said Trump was unpopular and would never win the nomination.”
Trump’s unfavorability ratings *are* very high. That, sadly, is just fact. His supporters are fervent, but more people don’t like him than like him. If we want a Republican in the White House, in order to get the votes those favorability ratings need to go up.
Unfavorably is not to be counted on as a reliable indicator in times of discontent. The one people dislike the most may get the vote if deemed the more effective.
“Unfavorability” is a worthless metric. Trump has won more votes than any Republican in primary history. These masses of people that don’t like him don’t seem to be bothered enough to actually vote against him.