Oklahoma Gov Kevin Stitt announces who he's tapping to replace Markwayne Mullin in the US Senate

Republican Oklahoma Gov. Kevin Stitt on Tuesday announced Alan Armstrong as his choice to fill Markwayne Mullin's U.S. Senate seat. 

The Senate on Monday voted 54-45 to confirm President Donald Trump's nomination of Mullin to serve as secretary of the Department of Homeland Security. Mullin is being sworn in Tuesday.

Stitt, who made the announcement during a press conference on Tuesday, described Armstrong in a post on X as "a proud third-generation Oklahoman, staunch conservative, respected business leader, and a devoted family man with an inspiring American Dream story."

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The governor noted during the press conference that Armstrong is stepping down from the board of Williams. 

The company's website describes Williams as an "energy infrastructure company."

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Sen. Rand Paul, R-Ky., was the only Republican to vote against Mullin's confirmation, while Sens. John Fetterman of Pennsylvania and Martin Heinrich of New Mexico were the only Democrats to vote for confirmation. 

Mullin cast a vote to green-light his own nomination.

Armstrong will not be able to run in the next election for the Senate seat he's now filling because Oklahoma state law stipulates that "a person who is a prospective appointee shall submit to the Secretary of State an oath affirming that the person will not file as a candidate for the office when it next appears on the ballot."

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Mullin is replacing Kristi Noem, who will instead serve as a special envoy for a security initiative pertaining to the Western Hemisphere.