If Senate Democrats planned to make an example out of retired Marine Corps commandant Gen. James Mattis, Leon Panetta may have pulled the rug out from underneath them. Democrats gave away the only tool with which to block presidential appointments three years ago under the leadership of Harry Reid, and have been searching for ways to flex what limited muscle they still have on Cabinet appointments. The nomination of Mattis gave them an opening, thanks to a statute requiring a Congressional waiver on recently retired flag officers for the Secretary of Defense position, but Barack Obama’s former SecDef endorsed Mattis for the position in a conversation with Josh Rogin:

Several Democratic lawmakers are raising concerns about Congress passing legislation to allow retired Marine Gen. James N. Mattis to be secretary of defense so soon after taking off his military uniform. But President Obama’s former defense secretary Leon Panetta believes Mattis should get the waiver and the job, he told me in an interview.

“It’s important that the Congress in the process of providing that waiver makes sure that Jim Mattis understands that he has to play a role not just on the military side but also on the civilian side. I think he does,” Panetta told me on the sidelines of the Reagan National Defense Forum on Saturday.

Congress should revisit the law anyway, Panetta argues:

Panetta also said the 1947 law mandating that a defense secretary be out of uniform for 10 years — later changed to seven — was “arbitrary” and was crafted in a different era when generals had a singular role as war fighters, whereas today’s generals have more diverse roles.

“That was in a time coming out of WWII when there was a tremendous reliance on military leadership during the war and a recognition that they were warriors while the people considering defense policy had to consider wider issues,” he said. “I believe that civilian control and civilian involvement in the Defense Department is an important principle, but I also don’t think a military background should be disqualifying.”

There are competing arguments on this point. The need to emphasize civilian control of the military is real, which is one reason why presidents have generally chosen elected officials (current or former) or civilian staff to other SecDefs as nominees. Panetta is an example of the former, having served as chair of the House Budget Committee before becoming OMB chief and chief of staff under Bill Clinton. Obama made him a surprise appointment to lead the CIA despite having no formal experience or oversight on intelligence, but even more surprisingly did a good job in that role — and earned bipartisan praise for his work at the Pentagon, too.

However, that should really be a question for the Senate in a confirmation process rather than a statute. If the Senate as a body is concerned that a SecDef appointment doesn’t appreciate the need for civilian control and oversight of the military, it can choose to reject his nomination. If enough Senators confirm the appointment, both chambers of Congress have oversight committees and budget authority to enforce that view — and the ability to impeach and remove a SecDef who doesn’t adhere to the rules. The statute may be unconstitutional in that regard, although no one has ever challenged it. If they waive the rule for Mattis, Congress ought to give serious thought as to whether it’s superfluous in the first place and just eliminate it altogether, as Panetta suggests.

If Democrats want to challenge Mattis’ nomination on other grounds, Panetta doesn’t leave them much room on that, either. A few days ago, Panetta sang Mattis’ praises to CBS’ John Dickerson:

“I like Jim Mattis a lot,” Panetta told “Face the Nation” host John Dickerson in an interview taped before Trump’s decision was announced. “He’s a tough general, spoke the truth, was a good advisor. I trusted his defense judgment. And so I think he’s got, you know, a lot of qualities that are important to a secretary of defense job.”

Senate Democrats might prefer Mattis anyway. He’s not a yes-man; he’s known for his independence and integrity, two qualities which might make them feel a bit safer in a Trump administration. If they want to score points on Trump, they’ll probably use Ben Carson to do it.