1. It’s the busiest Primary Day of the year so far.

Voters went to the polls in eight states: Alabama, California, Iowa, Mississippi, Montana, New Jersey, New Mexico and South Dakota.

Most of the attention this week has focused on California, which has an unusual open primary system. Democrats are vying for Republican-held congressional seats, the governorship is up for grabs, and the veteran senator Dianne Feinstein is running for re-election. We have live updates from our reporters throughout the state. Above, voting in San Diego.

And here’s what you need to know about the other seven states in play. We’ll have results here as they come in.