The senators pushing legislation Special Counsel Robert S. Mueller III from any risk of improper termination by President Donald Trump are not giving up.

Their bipartisan legislation expired at the end of the last Congress, and they announced Tuesday that they were introducing it again, despite continued opposition from Senate Majority Leader Mitch McConnell of Kentucky.

McConnell has argued the bill is unconstitutional.

While the two lead Republicans on the bill — South Carolina’s Lindsey Graham and North Carolina’s Thom Tillis — stressed that they did not think Trump or the Justice Department would seek to stop Mueller’s investigation of Russian interference in the American political system, the bill would nonetheless send an appropriate message.

“This bill’s protections will help ensure that our Justice Department will have the independence it needs to conduct fair and impartial investigations with appropriate reporting to Congress,” Tillis said in a statement. “This will, in turn, reaffirm the American people’s confidence in our nation’s rule of law and the principle that no one is above the law. We were able to build a bipartisan base of support for this legislation last year, and I look forward to working with my colleagues to build the additional support required to advance it through the Senate.”