Editor’s note: The presidential nominating contests in both parties will come down to the California primary.

For Democrats, 548 delegates are at stake — 11.5% of the total. For Republicans, 172 delegates are at stage — 6.9% of the total. Of those, for Democrats, 158 (29%) are divided proportionally on a statewide basis, while 317 (58%) are divided proportionally by congressional district, with each district providing between 5 and 8 delegates. The remaining 73 (13%) are “superdelegates.”

For Republicans, 13 (8%) are awarded statewide, with ten going to the candidate with the highest number of votes on a winner-take-all basis, and three going to “pre-determined” delegates (the State Chair, National Committeewoman, National Committeeman). Meanwhile, 159 (92%) are awarded by congressional district on a winner-take-all basis, with each district providing 3 delegates.

The result: a district-by-district battle in both parties, which we preview for you here.

CA-50: This San Diego County district is entirely landlocked, beginning in the hilly suburbs and the coastal mountains, and stretching east to the interior desert. It is as safe a Republican seat as any in the entire state of California, with registered Republicans outnumbering Democrats two-to-one. It is represented by Duncan Hunter, whose father was also the representative from the area. In February, Hunter became the first member of Congress to endorse Trump for president.

Prospects:

Democrats: Hillary Clinton will likely do well in this conservative district, though some Latino voters will support Sanders.

Clinton 4, Sanders 1

Republicans: Trump will win easily in this district, and Hunter will continue to be a key California surrogate for him.

Trump 3, Cruz 0, Kasich 0

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new e-book, Leadership Secrets of the Kings and Prophets: What the Bible’s Struggles Teach Us About Today, is on sale through Amazon Kindle Direct. Follow him on Twitter at @joelpollak.