Spread out over the first nine months of the year, primaries will set the stage for the 2018 midterm elections in November. These contests will be the first test of each party’s ability to field strong candidates in key pickup opportunities and fend off intraparty challenges.
The first elections will take place in March. Here’s what to watch for as the primaries pick up. And click here for Roll Call's comprehensive guide to every 2018 election from start to finish.