WASHINGTON — Sen. Markwayne Mullin, President Donald Trump’s nominee to lead the Department of Homeland Security, faced fellow senators on Wednesday at a confirmation hearing. And it didn’t begin well for the Oklahoma Republican, who has been tapped to take over DHS at a crucial time. The U.S. is locked in a war with Iran and the Trump administration faces a backlash for its aggressive immigration enforcement tactics. DHS funding lapsed on Feb. 13, leading to major delays at airports, and the two parties haven’t reached a deal. Sen. Rand Paul, R-Ky., the chair of the Senate Homeland Security Committee, used his opening statement to confront Mullin for reportedly calling him a “freaking snake” and saying he “completely” understands why a neighbor assaulted Paul in 2017. “Tell me to my face why you think I deserved it,” Paul told Mullin, while also bringing up Mullin's attempt to challenge a labor union leader to a fight during a 2023 committee hearing.…