Former Speaker John BoehnerJohn Andrew BoehnerBoehner says it's Democrats' turn for a Tea Party movement House Republicans find silver lining in minority Alaskan becomes longest serving Republican in House history MORE (R-Ohio) on Thursday took shots at Sen. Ted CruzRafael (Ted) Edward CruzO'Rourke raised .1 million from over 128,000 donors on campaign's first day O'Rourke on Israeli-Palestinian conflict: 'We don't have the best negotiating partners on either side' O'Rourke: 'I think we can win Texas' in 2020 MORE (R-Texas) and said he wouldn't be surprised if Hillary ClintonHillary Diane Rodham ClintonTrump mocks wind power: 'When the wind doesn't blow, just turn off the television' Trump's approval rating stable at 45 percent Kellyanne Conway: 'I think my gender helps me with the president' MORE ends up withdrawing from the presidential race.

Addressing the SALT Conference in Las Vegas, the former Speaker suggested that Democrats might have to turn to Vice President Biden to be their 2016 nominee.

Republicans have long speculated that the FBI investigation into Clinton's use of a private email server could result in criminal charges, wounding her candidacy.

Boehner, who resigned from Congress last fall amid an uprising from conservatives, also hammered Cruz, who was often his adversary in high-profile legislative fights.

"Thank God that guy from Texas didn't win" the nomination, Boehner said.

Boehner had called Cruz "Lucifer in the flesh" and a "miserable son of a bitch" before last week's Indiana primary sealed the Republican nomination for Donald TrumpDonald John TrumpTrump mocks wind power: 'When the wind doesn't blow, just turn off the television' Pentagon investigator probing whether acting chief boosted former employer Boeing Trump blasts McCain, bemoans not getting 'thank you' for funeral MORE.

"I got criticized by some satanic organization for giving Lucifer a bad name," Boehner quipped.

Boehner said anyone who thinks Trump can't win the White House should "just watch."

"This is going to be a presidential campaign like we've never seen before," he said.

And he said even if Republicans aren't unified around Trump, he said everyone shares the goal of winning the White House. He predicted the GOP will hold the House this fall despite predictions from Democrats that the chamber could be in play.