What he ought to do is keep highlighting his experience with border issues, and keep explaining his reasoning on what he did and why.
What he never should do is insult those of us that have a serious interest in the border issues. Twice in a row he has insulted people that he needs to vote for him. First we are racist then in the very next debate we are heartless. We have proven we can compromise on border issues, we really don’t need insults. I can agree to disagree on issues, being insulted is another matter.
So he said a dumb thing, one dumb thing. Is that reason enough to throw him under the bus, when we agree with him on 90% of everything else and he can get Obama out of the White House.
Let he/she who never inadvertently or in the heat of a moment insulted a loved one throw the first stone.
He probably also got bad advice, that instead of just being himself, to use emotional words, who knows.
We all agree it was dumb, I am sure he didn’t mean it that way and we need to put things in perspective.