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President-elect Joe Biden said Monday that he'll announce his defense secretary by the end of the week, and it looks like retired Gen. Lloyd Austin, a candidate who was once considered a long shot, is moving to the top of the list, three people familiar with the discussions told Politico.

Michèle Flournoy was initially seen as the frontunner, but Biden has faced pressure to nominate a person of color for the post, Politico notes. Subsequently, Austin and former Homeland Security Secretary Jeh Johnson, who are both Black, have emerged as top-tier contenders.

But the Biden transition team reportedly sees Austin as the safer, "controlled" choice — one of Politico's sources said "there would be less tension" surrounding an Austin nomination. That's because there are reportedly lingering concerns about Johnson's tenure in the Obama administration— he's been criticized for his record on expanding family detention, accelerating deportations, and approving civilian-targeting drone strikes, per Politico.

That doesn't mean there would be no drama if Biden does give Austin the nod. Some national security experts have pointed out he'd require a special waiver to get confirmed since he hasn't been out of the military for the required seven years, and he's also faced questions in the past about the military's role in training forces to combat the Islamic State in Syria, as well as allegations when he was leading U.S. Central Command that the command downplayed intelligence reports on the threat posed by ISIS. His command was cleared in an investigation in 2017. Read more at Politico.