Washington (CNN) 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."

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