As someone who didn't vote for you but is from the region chiefly responsible for your victory (Racine Wisconsin to be specific) my message is this.
If you are only going to keep only one of your campaign promises. It
better be ending the Free Trade Agreements, like NAFTA and CAFTA and the
TPP, and stuff directly related to that. Your strong turn out in
Wisconsin, Michigan and Minnesota was chiefly because of people who
voted for Bernie in the Primary (I voted for Bernie) and you in the
general because they voted chiefly on that issue. Because we are the
most hurt the ramifications of those agreements.
They don't care if you build the Wall or even necessarily want that. Or
about your Muslim Ban, or defeating ISIS. And certainly not any of the
typical Republican positions you espoused.
I was unwilling to vote for because I didn't trust you on this, given
how your businesses have themselves benefited from those agreements.
And because I was offended by the Xenophobia you appealed to.
IF however you actually do keep this promise, and the fears Mexicans and
Muslims have of your turns out to be unfounded. You might, just maybe
might win my vote for 2020.
But if not, you don't keep that promise, you will lose the people who chiefly gave this victory and have no hope of reelection.
The second promise I personally care about (in the sense of would like
you to keep it) is legalizing Marijuana. But for that I see no evidence
many people voted on that.