Donald J. Trump’s victory in the presidential race on Tuesday night capped a remarkable election in which several Democratic Senate candidates fell short and Republicans retained their majority in the House of Representatives. Here are some key takeaways from a stunning result that upended conventional expectations and set the stage for a drastic reordering of politics in Washington:

• Mr. Trump took the stage at the Hilton just before 3 a.m. and told his supporters that Hillary Clinton called him to concede the election. Striking a gracious note, he wished her well and said, “We owe her a major debt of gratitude for her debt to our country.”

• Reading from teleprompters and flanked by Gov. Mike Pence of Indiana and his son, Barron, Mr. Trump said he wanted to “reclaim our country’s destiny” and be bold and daring. He also called for unity and said that he hoped Democrats and Republicans would work together.