Senate teeing up Mattis waiver
© Greg Nash

The Senate is taking up a waiver to allow retired Marine Gen. James Mattis to serve as President-elect Donald TrumpDonald John TrumpPapadopoulos on AG's new powers: 'Trump is now on the offense' Pelosi uses Trump to her advantage Mike Pence delivers West Point commencement address MORE's Pentagon chief, with a vote expected on Thursday. 

Senate Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellThe Hill's 12:30 Report: Trump orders more troops to Mideast amid Iran tensions What if 2020 election is disputed? Immigration bills move forward amid political upheaval MORE (R-Ky.) brought up the waiver on the Senate floor less than an hour after it passed the Senate Armed Services Committee. 
The move kicks off up to 10 hours of debate, though lawmakers aren't expected to eat up the entire allowed time. McConnell encouraged any senators who wanted to speak to come to the floor quickly. 
"We're on the Mattis waiver. Anybody who would like to debate, please come over," he said.
Sixty votes in the Senate are needed to grant Mattis the waiver under a deal between Democrats and Republicans worked out last year. It would allow the former general to sidestep a current law requiring the Defense secretary to be out of uniform for at least seven years. 
Mattis retired from the military in 2013 and will be the second defense secretary to receive a waiver. 
Though Democrats initially raised concerns about linking the waiver to a spending bill late last year, objections over his nomination quickly fizzled. 
Only three Democratic senators — Kirsten Gillibrand (N.Y.), Richard Blumenthal (Conn.) and Elizabeth Warren (Mass.) — voted against the waiver in committee earlier Thursday. 
Mattis stressed during his committee hearing that he understands the difference between serving in civilian leadership and military service. 
"I recognize my potential civilian role differs in essence and in substance from my former role in uniform," he said. "Civilian control of the military is a fundamental tenet of the American military tradition."