If Republican political insiders are fretting about Donald Trump's impact on the party if he becomes the nominee, they need to start convincing their voters.

According to a new national Quinnipiac poll, 73 percent of Republican voters say Trump would have a good chance of defeating the eventual Democratic nominee.

That's compared with 63 percent of GOP voters who say this about Marco Rubio, 59 percent who say it about Ted Cruz and 55 percent who say it about Ben Carson.