Resolves to the party that wins the November 7, 2028 U.S. House election in California's 21st District: whichever district is numbered 21 on the map in effect for that election. N/A if that map has no district numbered 21.

Only the party matters: a Democratic or Republican nominee counts as that party even if also listed on other parties' lines. Anyone else resolves to Other, or to their own answer if one has been added.

Resolves on the certified result, or earlier once the AP has called the race and no recount could change it. N/A if no election for this seat is held.