"I'll have to see how I'm being treated by the Republicans," Trump said. "Absolutely, if they're not fair, that would be a factor."

The Republican businessman, who is leading most national polls, is under attack from many leaders in his own party who view his candidacy as a sideshow that could harm the GOP brand.

But as The New York Times previously reported, what some party higher-ups fear most is Trump launching a third-party campaign that could pull more votes from the Republican nominee than the Democrat in the general election.

"You've got to keep him in the tent," former Rep. Tom Davis (R-Virginia) told the newspaper. "He just wreaks havoc, and every vote he takes comes out of our hide."

A poll released earlier in this week may confirm that fear. Testing a hypothetical three-way matchup among Trump, former Gov. Jeb Bush of Florida (R), and Democratic front-runner Hillary Clinton, a Washington Post/ABC survey found Clinton (46%) easily ahead of Bush (30%) and Trump (20%).

Trump, speaking to The Hill about a potential third-party bid, singled out the Republican National Committee in particular for being unfair to him.