Trump and his supporters trumpet the polls when they show him winning. If they don't show him winning, they say you cannot trust the polls.
Trump's base is secure. Reaching beyond that base, even against Hillary, may not be possible. He's secured his base by blasting and insulting many people and groups, which proves that he's not PC. This approach worked well to obscure his own history of supporting Hillary and people like Hillary and being a crony capitalist. No one can confuse the former Democrat donor, former independent, and now Republican presidential candidate of being an ideologue. Far from it. He changes his beliefs to fit his needs. Now, he needs to be president. But success will require some votes from people outside the %30+ who support him now. As mercurial and ungrounded in principles as he is, he can flip on some positions to maybe pick up a little more support, but I still doubt that he's going to be able to break out beyond his fervent supporters. Trumps using the bludgeon when the rapier would have worked just as well has defined by his example. It's appeal has its limits. Trump is a pseudo conservative. It's possible too many of them will be turned off to vote for him, too.
Interesting thought line there, I never really thought about him just changing positions after getting rid of competition from his own party. Slip the the right, slip back to the left, as though the voting electorate is being lead by the nose... That is why Character matters (and you judge by past fruits).
Go Cruz Go...