Washington — The Senate confirmed Markwayne Mullin as secretary of the Department of Homeland Security on Monday, finalizing President Trump's shakeup of DHS following months of scrutiny of Kristi Noem's leadership.In a 54-45 vote, the Senate confirmed Mullin, an Oklahoma Republican who's been in the Senate since 2023. Democratic Sens. John Fetterman of Pennsylvania and Martin Heinrich of New Mexico voted in favor of Mullin's confirmation. Sen. Rand Paul of Kentucky was the sole Republican to oppose Mullin.The upheaval at DHS culminated in Noem's ouster as secretary earlier this month. Noem's handling of two deadly shootings by federal agents during the immigration crackdown in Minneapolis in January prompted criticism from Democrats and Republicans and kickstarted an impasse over funding for the agency that has persisted. But it was criticism over Noem's advertising spending at a congressional hearing days before her ouster that appeared to seal her fate.…