Update: Read our analysis of the primary night in California, and about races from New Jersey to Montana.

LOS ANGELES — Since President Trump’s election, politicians in solidly Democratic California have embraced their role as the leaders of the resistance against the White House. Democrats are counting on the state to flip several congressional seats and help the party win control of the House.

Californians go to the polls on Tuesday to vote in what is known as a “jungle primary” — voters from any party can choose a candidate, and the top two vote-getters will make it to the November ballot. It is one of the most anticipated voting days in the lead-up to the fall midterm elections, with Republicans eager to prove they can still dominate in suburban and rural districts.

Here’s how to get up to speed:

• In many contests, including the governor’s race, the biggest question is whether one of the two major parties will be shut out entirely. Democrats are trying to avoid self-inflicted disaster in the House. Start here to understand what’s at stake in the major races.