Let's say Trump got a majority of those Americans who voted, and every one of them had to know what he was saying he'd do, just in case they forgot about last time.

However, a good forty percent of Americans who can vote do not. Some choose to opt out of the system because of disillusionment or despair, others are blocked from voting by discriminatory laws. Unless we reach, register and motivate these people to vote, Republicans will keep winning even if they are a minority.