Oklahoma Gov. Kevin Stitt on Tuesday chose energy executive Alan Armstrong to fill Sen. Markwayne Mullin's seat through the end of year.

The Senate has voted to confirm President Trump’s pick, Sen. Markwayne Mullin, R-Okla., to lead the Department of Homeland Security. NBC News’ Sahil Kapur reports on the Senate vote.

President Trump tapped Mullin, a first-term Oklahoma GOP senator, to replace Kristi Noem as homeland security secretary earlier this month.

The U.S. Senate on Monday (March 23) confirmed President Donald Trump's nominee for Homeland Security secretary, Markwayne Mullin, to replace outgoing Kristi Noem, heralding a shift in leadership as public support for Trump's immigration crackdown has fallen.

Markwayne Mullin, a Republican senator from Oklahoma, will replace outgoing Homeland Security Secretary Kristi Noem.

Sen. Markwayne Mullin is confirmed as Homeland Security secretary, three weeks after President Trump fired Kristi Noem from the post.

The Senate on Monday night confirmed President Donald Trump's nomination of Sen. Markwayne Mullin to lead the Department of Homeland Security. Mullin advanced out of Senate committee last week after a fiery confirmation hearing.

The Senate on Monday confirmed Sen. Markwayne Mullin (R-Okla.) to lead the Department of Homeland Security (DHS) after President Trump dismissed his first Cabinet official. Mullin earned support from