1) Emphasize blue collar concerns. Target this groups economic concerns. Trump has owned this demographic, getting voters.
2) Wage stagnation. Ditto. Trump has resonated here.
3) Emphasize the need to stop obeying political correctness as an excuse to avoid being called names, like racist, etc. Show you are willing to fight back equally, but more intelligently, than Trump.
4) Bring up that Trump wants a big door on that wall, revolving immigration to allow illegals unless totally criminal, to simply come back in, defeating much of the purpose of even having a border barrier, leading to de facto amnesty anyway. Show your plan avoids that.
5) Bring up Trump secret interview showing possible immigration weaknesses and opinions contrary to what he’s peddling now. Release the tapes, now! Claim he is hiding something.
6) What is Trump hiding in his taxes? Like the argument over Cruz eligibility, it might sway voters if they think a bombshell is in there and he won’t release until after he’s nominated in like July. That’s too late as a judge could ruin him or the material itself for the Fall, so we have to know now for safety. Release the return, Donald! Again, Democrats will exploit this, so out with it now.
7) Claim his earpiece was not the issue, since he responded after and seemed to know the name of the person, Duke. It’s not credible he did not know who he was, and in fact he DID know him so he’s already lied at least once for sure. He knew him definitely in 2000, and a few months ago when Duke mentioned him in some interviews, and a few days prior to the gaffe he had involving the earpiece claim.
8) Someone his age cannot possible not be aware of the KKK and it’s meanings.
9) He and his father were involved in a case in the early 70’s involving possible discrimination against Black renters. Explore.
10) He is supported by StormFront, ROK, (Return of Kings a sexist anti-feminist pro-sexual abuse of females site) and other White Nationalists. He might want to explain why those folks are so into him, even if he claims not to support them back.
11) Ask why so many racist supporters are at his rallies calling names in racial terms, some say, to Black demonstrators and participants, some of whom have been caught on video recently being removed amid angry mobs who hurl insults. Racial?
12) Ask him how he intends to make Mexico pay for the wall, in precise terms. Laugh at his explanations.
13) Ask him basic questions in “trap” form about government, SCOTUS pick processes, etc. so that he makes a fool of himself on television when he fails to answer correctly (nuclear triad, etc.) since he does not know anything in detail. He and his supporters cannot answer on health insurance specs, other than “sell insurance outside state lines” and a few canned answers, so he needs to be pressed to show his lack of policy knowledge in detail.
Job creation should be hit heavily, too. And the need to empathize with the poor and working poor. Show you care.
Cruz: “I’m the true outsider in the race, not Trump. He’s a deal maker that funded Pelosi and Reid who also financed the gang of 8, so his immigration bonafides are phony. I stood up to Mitch. M. I opposed the bailouts, I held serve on the debt ceiling fight, I am hated by the Establishment because you can trust Ted, I only wanted them and us to keep our words to our constituents, which is what I did every time once I got elected and will continue to do so after becoming president.”
That’s the basic list, add any I’ve missed in comments!