Markwayne Mullin is appearing before senators for a Department of Homeland Security confirmation hearing as President Donald Trump’s deportation push faces rising backlash. Wednesday's hearing is Mullin’s first opportunity since being nominated to publicly present his plans for DHS. If confirmed, the Republican Oklahoma senator would replace Kristi Noem, whom Trump fired this month. Democrats will likely press Mullin regarding aggressive immigration raids and claims of rough treatment by officers. The hearing comes during a partial government shutdown that leaves airport security screeners unpaid and airport lines growing. Senators also will likely question Mullin about the Federal Emergency Management Agency, which faces major reforms and funding delays.