Former Florida Gov. Jeb Bush responded to a poll promoted by Donald Trump — which showed the billionaire holding on to 68 percent of his supporters if he ran as an independent — by floating the theory that the GOP frontrunner’s candidacy might be a false flag operation planted by Hillary Clinton.

Maybe Donald negotiated a deal with his buddy @HillaryClinton. Continuing this path will put her in the White House. https://t.co/AlvByiSrMn — Jeb Bush (@JebBush) December 8, 2015

The tweet may have been in jest, and otherwise Bush has been one of the more vocal critics among the 2016 field of Trump’s hardline stances that including banning Muslims from entering the U.S. (Republican National Committee Chair Reince Priebus — who persuaded Trump to sign a loyalty pledge to the GOP — said he didn’t agree with the Muslim ban, but refused to criticize Trump further.)

But others on the right have speculated since early on in Trump’s White House run that the GOP frontrunner’s candidacy was a ploy by Democrats to rile Republicans.

Rep. Carlos Curbelo (R-FL) said over the summer that there was a “small possibility” that Trump was indeed a Democratic plant.

Trump swiftly shot down the theory:

“Believe me — from Hillary’s standpoint, the one person she doesn’t want running against her is Donald Trump,” he said at the time.