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-49: This coastal district begins at the southern end of Orange Country but is largely within San Diego County, taking in several coastal cities and suburbs, as well as the U.S. Marines base at Camp Pendleton. It is represented by Republican Darrell Issa, who was a vocal supporter of Sen. Marco Rubio (R-FL) in the primary. Military votes — which are not confined to the base but extend throughout the San Diego metropolitan area — will determine the primary winner in both parties.

Prospects:

Democrats: Though San Diego is warm, this is one county where Democratic voters are unlikely to “feel the Bern.”

Clinton 5, Sanders 1

Republicans: Cruz will keep the race tight — especially if Issa endorses him — but Trump’s military vote will prevail.

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.