Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, said he didn't think President Donald Trump would fire special counsel Robert Mueller and suggested the president let the Russia probe "work its course," CNN reported Friday.

"I just don't think the president, as unpredictable as he is, would fire Mueller. And I take the view, and I said so maybe not directly to the president, but indirectly to the president – just let this work its course," Grassley told CNN.

When asked if he thought it would be all right for Trump to fire Mueller, Grassley responded, "Heaven's, no."

On Thursday, it was reported Trump threatened to fire Mueller last June, but was talked out of it by White House counsel Don McGahn.

That report has reignited the debate among Democratic lawmakers about legislation in the Senate that would give Mueller and other special counsels protection from political pressure. Grassley said he was "surely open to considering those bills."

The legislation faces wary Republicans, many who see no need for it, while Democratic Sens. Chris Coons of Delaware and Cory Booker of New Jersey are calling for more protections for special counsels.

"It is more important than ever for Congress to act to protect the independence of the Department of Justice, including the special counsel investigation . . . These reports make clear that we need to act." said Coons, who partnered with Sen. Thom Tillis, R-N.C., on one of the bills.

"I just hope that Congress now rallies around the idea that here is a good piece of legislation to make sure that we have a check-and-balance in the judiciary branch, on the president's powers," Booker said, who worked with Sen. Lindsey Graham, R-S.C., on a similar bill.

"I would say that reactions before this broke were, 'Hey, this is a good bill. This is good legislation. But, what's the hurry? What's the urgency?' Now, I think what we're going to hear is a more sober analysis of how to move forward," Booker added.

The two bipartisan bills are similar in offering protection for a special counsel but differ on the process for how one could be fired, such as in the case of misconduct, dereliction of duty, incapacity or conflict of interest.