Well, it comes out if he's the one running as a Republican. If he's not, just use his rhetoric to hurt the republican who is running.
"Donnie talks a good game, but let's look at his record:"
or
"You know, I disagree with just about everything Donald Trump says, but I do agree with him that cutting social security and medicare like my opponent wants to do is dumb."
Rhetorically Trump is populist on economics. His one big bill on taxation and economics was the old time religion.
Agreed. In no way am I fooled by his bullshit, but that rhetorical difference may have opened up some possibilities around the edges here and there.
"Donald Trump doesn't agree with Republicans on X" might open a few minds here and there.
Well, it comes out if he's the one running as a Republican. If he's not, just use his rhetoric to hurt the republican who is running.
"Donnie talks a good game, but let's look at his record:"
or
"You know, I disagree with just about everything Donald Trump says, but I do agree with him that cutting social security and medicare like my opponent wants to do is dumb."