GOP senator: Nothing wrong with Republicans challenging Trump in 2020

Sen. Susan CollinsSusan Margaret CollinsSenate rejection of Green New Deal won't slow Americans' desire for climate action Senate GOP poised to go 'nuclear' on Trump picks Overnight Health Care: CDC pushes for expanding HIV testing, treatment | Dem group launches ads attacking Trump on Medicare, Medicaid cuts | Hospitals, insurers spar over surprise bills | O'Rourke under pressure from left on Medicare for all MORE (R-Maine) said Sunday that there's "nothing wrong" with a crop of Republicans considering a primary challenge to President TrumpDonald John TrumpTrump: 'Haven't thought about' pardons for Mueller target Pence: Rocket attack 'proves that Hamas is not a partner for peace' Conservation remains a core conservative principle MORE in 2020.

"I see nothing wrong with challengers," she said on CNN's "State of the Union." "That is part of our democratic system."


Several prominent Trump critics within his own party are considered possible candidates in 2020, most notably Ohio's GOP Gov. John Kasich. Kasich says he's "very seriously" considering a run.

"It's up to those individuals to decide whether or not they're going to oppose the president," Collins continued. "They would probably have an uphill climb."

Collins also declined to endorse Trump as the Republican nominee, saying she's not ready to talk about 2020 yet.

Collins, who is considered a top target for Democrats in 2020, said "I'm going to talk about 2020 in 2020" and focus on the politics of the day now.

"I'm worried that we're getting into perpetual campaign mode," she said.

Several sitting presidents have been challenged in the primary for their second term, most recently former President George H.W. Bush in 1992 by Pat Buchanan.

Collins also discussed Trump's former attorney, Michael Cohen, and federal prosecutors implicating the president in campaign finance violations, saying it was "not a good week" for Trump.

"Let me point out that there are a lot of unanswered ethical, legal and factual questions but clearly this was not a good week for President Trump, nor for his campaign organization and these allegations are concerning," she said. "But we need to wait until we have the entire picture. And that's why it's so critical that the special counsel be allowed to complete his investigation unimpeded so that we can have the full picture."

Cohen was sentenced last week to three years in federal prison for a series of crimes he committed while working for Trump, including campaign finance violations stemming from payments to two women alleging to have had affairs with Trump. 

--This report was updated at 12:46 p.m.