Trump voters aren't going to stop voting for him because he said something stupid. If that were any criterion they'd never have voted for him in the first place.
They need to be shown how he is the quintessential part of the American elite that has fecked over everyone else in American society for the past 50+ years (Still accellerated by Regan, & W). He has to be shown as the employer of undocumented workers, as the father of unsupported children, as the owner of hundreds of foreign cars and hardly any American.
The great thing about his supporters is they don't care about truth. One can convince them of nearly anything using a stupid enough argument. I admire Fox in a way for it. Bullshitting shouldn't be as easy as they make it look. Democrats need to do it too. No more rising above. Get in there, get dirty, and defeat that son of biatch.