2. The 2020 presidential race gets into gear.

Senator Elizabeth Warren of Massachusetts is the first major candidate to enter what is likely to be a crowded Democratic primary race. The winner will challenge President Trump in 2020.

“The problem we’ve got right now in Washington is that it works great for those who’ve got money to buy influence, and I’m fighting against that,” Ms. Warren said in a statement outside her home, above, where she was joined by her husband and their dog. Our video team compiled a blow-by-blow history of the fractious relationship between Ms. Warren and Mr. Trump.

Even though the earliest voting is 13 months away, Julián Castro, the former federal housing secretary and San Antonio mayor, also formed exploratory committees this month. Several more candidates are expected to declare in coming weeks. They’re all roughly on schedule, our politics team says.