Sen. Susan Collins (R-Maine) raised eyebrows Monday by declining to say whether President Trump would be re-nominated by the GOP in the 2020 presidential election.

"Do you think he will end up the party's nominee?" an MSNBC host asked.

"It's too difficult to say," said Collins, who recalled that she did not support Trump during his campaign and wrote in Paul Ryan's name last November.

'Blood on Your Hands!': Charlottesville Council Meeting Devolves Into Chaos

Kaepernick 'Artifacts' Will Be in Smithsonian Black Lives Matter Exhibit

Corey Lewandowski, former Trump campaign manager, downplayed the idea this morning on Fox Business Network, arguing Collins' remark carries "no weight."

"If Donald Trump runs, he will be the Republican nominee. There's no question about that," he said. 

Collins opposed Trump and most of her Senate colleagues on repealing ObamaCare, maintaining that the replacement proposals were not good enough. 

She was joined by Republicans John McCain and Lisa Murkowski in voting with Democrats to block the repeal a few weeks ago. 

Other Republicans have been highly critical of Trump in recent weeks, with Sen. Bob Corker (R-Tenn.) going as far as to question Trump's "stability" and "competence" after Charlottesville.

Stuart Varney asked how any Trump supporter can be confident that a "growth agenda" will be accomplished with Republicans so divided. 

Lewandowski said he shares the same doubts after Republicans failed to deliver on their promises to repeal ObamaCare. 

"There should be accountability at the ballot box [for Republicans]," he said. 

Watch the interview above.

'Art of the Deal' Ghostwriter Says Trump Will Resign: 'The Last Days of Nixon'

'He Can't Recognize Domestic Terrorists': House Dem Drafts Trump Impeachment Bill

'Take a Sledgehammer to It': 2 Bill Clinton Accusers Want SD Statue to Come Down

Romney Slams Trump for His Charlottesville Response, Calls for Apology