Three months out from the big November election, around a third of all states have yet to hold (non-presidential) primaries. This Tuesday, Democrats and Republicans in Missouri, Michigan, Washington and Kansas are heading to the polls to pick which candidates will appear on their ballots in the fall.
The electoral fate of a couple endangered House incumbents hangs in the balance on this packed primary day. In Missouri, a progressive "Squad" member faces a serious challenger backed by centrist forces, and in Washington, one of only two remaining House Republicans who voted to impeach President Donald Trump is being challenged by not one but two Trump-endorsed opponents from his right.
Meanwhile, both parties will lock in their nominees for Michigan's critical Senate race, and Republican primary contests are likely to determine Missouri's next governor and attorney general. In battleground House districts, the fields will be set for competitive fall contests, while in safe red and blue districts, ideological lines will be drawn as candidates duke it out in primaries tantamount to election.
As usual, 538 reporters and contributors are breaking down the election results as they come in with live updates, analysis and commentary. Follow along with our full live blog below!