A potential promotion for Herman Cain appears to be in doubt after several GOP senators expressed concern about the former WSB Radio talk show host filling a vacancy on the Federal Reserve board.

The ex-presidential and Georgia U.S. Senate candidate has yet to be formally nominated for the advisory position, but he was a topic of discussion during a closed-door meeting among Republican senators on Tuesday. Several officials have since suggested  that Cain will face a fraught confirmation process given past sexual harassment allegations and his position as a Trump surrogate.

President Donald Trump said last week he was recommending the Stockbridge businessman for the advisory position, which helps set the nation's monetary policy. The seven-member board has a reputation for being independent and apolitical.

Sen. John Thune of South Dakota, the Senate GOP's top vote counter, said “there are concerns that are being voiced to the administrations about (Cain’s) qualifications.”

The White House is "probably going to hear from a number of our members about concerns that they have," he told Politico. "Whether or not that gets them to make a course change or not, I don't know."

Several other Republican senators, including Mitt Romney of Utah and Kevin Cramer of North Dakota, were also quoted casting doubt on Cain’s confirmation chances.

Cain, 73, previously served as chairman of the Kansas City branch of the Federal Reserve before returning to Georgia to attempt a political career that included an unsuccessful bid for U.S. Senate in 2004. After ending his radio program on News 95.5 and AM 750 WSB last summer, Cain went on to co-found a pro-Trump super PAC.

Cain needs to win over 50 senators to be confirmed. With Democrats unlikely to provide any votes, Cain can only afford to lose three Republicans to keep his nomination afloat, assuming Vice President Mike Pence would cast a tie-breaking vote.

Most executive branch nominees lay low during the Senate confirmation process, but Cain has continued to post daily videos on his Facebook page railing about liberals and the news media and discussing economic issues. On Monday, he called criticism of his expected nomination “ridiculous.”

"Because I ran as a Republican for president and the U.S. Senate, and because I am an outspoken voice of conservatism, an outspoken voice of the Constitution and the laws, I'm being attacked," Cain said in a Facebook post.

Cain is currently undergoing a background check. The White House did not immediately respond to a request for comment.

Georgia U.S. Sen. Johnny Isakson, who defeated Cain for the GOP Senate nomination in 2004, declined to share his thoughts on his former opponent’s Fed nomination on Tuesday.

“It’s not in my area of responsibilities right now,” said Isakson, who is not a member of the Senate Banking Committee, which will take a first crack at any Fed nominees.

One member of that panel, Georgia Republican David Perdue, has signaled that he will stick by Cain. The Trump ally previously said Cain would be a “great addition” to the advisory board.

Senate Majority Leader Mitch McConnell was more noncommittal.

“Well, we’re going to look at whoever (Trump) sends up, and once he does, we’ll take a look at it,” the Kentucky Republican told reporters on Tuesday.

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