Kristi Noem, who oversaw United States President Donald Trump’s aggressive immigration crackdown and faced bipartisan criticism in hearings this week, will leave her role as homeland security chief at the end of the month. Trump will tap Oklahoma Senator Markwayne Mullin to replace her, he said on his Truth Social platform, a move that would require US Senate confirmation. Noem, a former governor of South Dakota, became one of Trump’s most high-profile Cabinet secretaries with social media posts...