Congress returns to a changed Washington after Democrats trounced Republicans in the midterm elections. Also Monday, Stephen Miller becomes President Donald Trump’s new chief of staff as the White House doubles down on the president's political threats despite the landmark GOP losses. It's the start of a six-week lame-duck sprint for Congress as Republicans try to wrap up work before Democrats take charge in January. Newly elected lawmakers have arrived on Capitol Hill for orientation sessions. Jubilant Democrats, with families in tow, appear emboldened by the party’s sweep of power. The trickle of Republicans coming in spoke soberly of the GOP’s challenges ahead.