Trump's speech (https://www.youtube.com/watch?v=xUW2-MUonbo embedded below):What is he really, really wrong on? (not an exhaustive list:)
Israel: It's being run by land thieves.
Iran: It's not seeking nuclear weapons.
Mubarak: He was a brutal dictator.
Guns: He's talking as if it's all or nothing.
Coal and oil: He's completely wrong on global warming. It's real. It's ramping up, up, up because of human carbon burning.
Obamacare: While I support single-payer, Obamacare has not been job killing. Millions have coverage where they had none before.
Tax cuts: He apparently believes in expansionary austerity. Austerity doesn't create better paying jobs, jobs, jobs but does the exact opposite. The rich who benefit from massive tax cuts don't plow it back into the general economy. They don't have a tendency to spend it but rather save more. It's the lower classes that spend more of the increases in their incomes; and even if they paid no taxes (which they shouldn't), that would still not rev up the economy enough. We need more, not less, public spending.
What is he most right about? Hillary.