While everyone is starting to think about the 2020 presidential race and consider what the Democratic candidates are proposing to do if they win, there's an unspoken presumption behind their ambitious plans, that they would actually stand some chance of passing through Congress. That will only happen, however, if Democrats control both houses.
Which means that the contest for the Senate, which Republicans now control by a 53-47 margin, will be nearly as important as the presidential race.
Democrats just got a particularly intriguing candidate to run for one of the small number of vulnerable Republican seats: Mark Kelly, former astronaut, gun safety advocate, and husband of former congresswoman Gabrielle Giffords, announced that he'll be running in Arizona for John McCain's old seat, which is currently held by Martha McSally.