At the beginning of last year, Mike Pompeo ruled out a 2020 Senate run, saying he would serve as Donald Trump’s secretary of state for as long as the president allows. But with impeachment entangling his boss, and Mitch McConnell working overtime to recruit him, the Pompeo rumor mill has continued to churn. In that uncertainty, which Pompeo himself has fed, several candidates have quietly begun to line up behind him, positioning themselves to replace him at State.

Three people who’ve spoken to the president directly about the matter told Washington Post that Trump has “been tossing around names for Pompeo’s successor with lawmakers and officials.” Two figures have emerged as leading contenders for Pompeo’s would-be replacement: national security adviser Robert O’Brien and Treasury secretary Steve Mnuchin. O’Brien, who replaced John Bolton as national security adviser, reportedly charmed Trump as the State department’s lead hostage negotiator, and has been rewarded with a growing portfolio. He’s also endeared himself to Jared Kushner, the president’s son-in-law and senior adviser, and to Pompeo himself, perhaps making him a natural successor.

Mnuchin would be a less intuitive pick. Unlike Trump and Pompeo, the Treasury secretary has taken a less hawkish approach to China, putting him out of step with the rest of the administration on a key foreign policy front. Still, Mnuchin remains close to the president, as evidenced by his rare longevity in the Trump administration. In a White House characterized by infighting and high turnover, surviving in Trump’s cabinet for three years makes him a competitive candidate by default.

Of course, their abilities to appease Trump notwithstanding, each comes with liabilities. Mnuchin was barely confirmed for his current job thanks to his lack of experience. His qualifications to serve as America’s top diplomat are even thinner, raising questions both about his ability to be confirmed and to fulfill his duties. O’Brien is reportedly seen as one of the more competent officials in Trump’s orbit, rooted in a traditional conservative foreign policy approach, but remains somewhat green behind the ears. “I think the greatest challenge he will have is his relative lack of experience inside the U.S. government, and with the interagency process,” Richard Fontaine, the chief executive of the nonpartisan Center for a New American Security, told the New York Times of O’Brien in September, as he took over for Bolton.

Such concerns could open the door to other figures who have indicated interest in Pompeo’s job, including Ambassador to Germany Richard Grenell, Senators Marco Rubio and Tom Cotton, and deputy secretary of state Stephen Biegun, who would become acting secretary of state should Pompeo decide to launch a 2020 Senate campaign. He hasn’t yet signaled that he’ll do so. But the barely concealed jockeying suggests McConnell’s overtures to Pompeo may actually be working—particularly Republican leadership believes their Kansas senate seat is in danger. “He loves Kansas, he loves the people of Kansas,” Trump said last month, suggesting he’d be open to Pompeo mounting a bid. “If he thought there was a chance of losing that seat, I think he would do that and he would win in a landslide because they love him in Kansas.”

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