Trump running as an Independent could spell doom for the GOP

While he surges in the polls, some within the Republican establishment have begun wishing Donald Trump would leave the race.

Trump responded with a threat that could spell huge trouble for the GOP: a third-party run.

"So many people want me to, if I don't win ... I'll have to see how I'm being treated by the Republicans," he said in an interview with The Hill.

For now, he's decidedly running as a Republican, and he's even admitted an Independent run could be bad for the party.

"The best way of defeating the Democrats, and probably Hillary – I think it's going to be Hillary – is to run as a Republican. If I do the third-party thing it would be, I think, very bad for the Republicans," Trump said.

See images of Trump on the campaign trail:

But the Republican party has not fully embraced the brash White House hopeful, even if some of the voters have.

The head of the RNC reportedly asked Trump to tone down his controversial rhetoric after his critical comments of immigrants and Mexicans specifically.

After Trump's comments about John McCain, the GOP said in a statement, "There is no place in our party or our country for comments that disparage those who have served honorably."

"I think that candor, I think voters are really hungry for, and outside of Washington I think there's a section of the Republican Party that that really resonates with," said The Hill reporter Kevin Cirilli.

That's part of why an Independent run from Trump could create such a problem, as his appeal with Republican voters could pull some from voting for the GOP candidate in a three-way race. Businessman Ross Perot's candidacy is largely considered to have been a significant factor in why Bill Clinton beat incumbent George H.W. Bush in 1992.