Maine Republican Sen. Susan Collins said on Sunday that Congress should pass legislation to protect special counsel Robert Mueller following reports President Donald Trump considered firing him last June.

But at the same time, Collins said in an interview on CNN's 'State of the Union' that she ultimately had faith in Deputy Attorney General Rod Rosenstein, who has direct authority over the probe.

'It probably wouldn't hurt for us to pass one of those bills,' Collins said, adding, 'There are some constitutional issues with those bills, but it certainly wouldn't hurt to put that extra safeguard in place given the latest stories, but again, I have faith in the deputy attorney general.'

Collins' comments came in response to news that last June Trump moved to fire Mueller, and that White House counsel Don McGahn refused the order. Collins said Sunday she understood the episode to be Trump having a 'bad idea.'

'He talked with his counsel, who explained to an angry and frustrated president why it was a bad idea,' Collins said. 'And that was seven months ago and the White House counsel is still on the job, and Mr. Mueller is still aggressively investigating, and that's as it should be.'

8 times since June the White House denied Trump was considering firing Mueller

Collins said likewise that firing Rosenstein would be a 'terrible mistake' and would recall the 'Saturday Night Massacre,' where then-President Richard Nixon sought to remove the special prosecutor investigating him, prompting leaders of the Justice Department to resign rather than quash the probe.

'That didn't end very well,' Collins said, alluding to Nixon's eventual resignation in disgrace.

In a separate interview on the same program, West Virginia Democratic Sen. Joe Manchin said it sounded like Trump 'blew off' about the investigation, but that it would be 'premature' for Congress to debate protections for Mueller.

House Majority Leader Kevin McCarthy, a California Republican, made a similar case on NBC's 'Meet the Press.'

'I don't think there's a need for legislation right now to protect Mueller,' McCarthy said. 'Right now, there is not an issue, so why create one when there isn't a place for it?'

South Carolina Republican Sen. Lindsey Graham said on ABC's 'This Week' that he saw 'no evidence' Trump is currently trying to fire Mueller, but pointed to legislation he has sponsored to protect the special counsel.

'It's pretty clear to me that everybody in the White House knows it'd be the end of President Trump's presidency if he fired Mr. Mueller,' Graham said.