A lower profile race will play out in the rural and northern First District, which Representative Doug LaMalfa, a Republican, represented for years until his death in January. As a result, two elections will appear on the ballot for some voters on Tuesday: a special election to fill the remainder of Mr. LaMalfa’s term in the existing district, and a regular election for a full two-year term in the new district created by Proposition 50. A Republican, Assemblyman James Gallagher, is expected to prevail in the special election, but the new map should favor the Democratic candidates: Mike McGuire, a leader in the State Senate, and Audrey Denney, an educator from outside the party establishment.
In both of those contests, the top two vote-getters will advance to a second round of voting — with one exception in the special election. In a quirk of California election law, if a candidate wins more than 50 percent of the vote in that race, they will be declared the winner and there will be no runoff on Aug. 4.
Who will emerge from primaries in seats held by veteran Democrats?
The youth movement has come for California. A host of longtime senior incumbents face primary challenges, but the most serious appear to be to Representative Brad Sherman, 71, in Los Angeles, and Representative Doris Matsui, 81, in Sacramento.
Both representatives are expected to win a top-two spot in their respective primaries. So the bigger question on Tuesday is whether their intraparty challengers will survive and force them into competitive November battles in their safe Democratic districts.
In a high-profile San Francisco contest, the incumbent, Ms. Pelosi, is retiring, shifting attention to which Democrat will emerge to replace her. State Senator Scott Wiener has led in polls, with two progressives, Connie Chan and Saikat Chakrabarti, duking it out for second place.
Mr. Chakrabarti is a wealthy former tech executive who has self-funded his campaign, but Ms. Chan received Ms. Pelosi’s endorsement, and Mr. Chakrabarti has been dogged by questions about why his former boss, Representative Alexandria Ocasio-Cortez, has not endorsed him.
