Amid an ongoing Department of Homeland Security shutdown and heightened tensions over immigration enforcement, newly confirmed U.S. Secretary of Homeland Security Markwayne Mullin stopped in Astoria Wednesday and toured Coast Guard facilities at the mouth of the Columbia River.Mullin visited U.S. Coast Guard Air Station Astoria in Oregon and the Cape Disappointment Motor Lifeboat School in Washington. Also in attendance were U.S. Rep. Marie Glue…