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-53: California’s “last” district includes the inland portions of the city of San Diego, as well as the city’s eastern suburbs. This is where San Diego’s workforce largely lives, and the embattled Chargers play football. It is a safe Democratic seat, represented by Susan Davis, whose key vote in recent years was her decision to support the Iran deal. Unlike the areas to the south and east, this district has a relatively low minority population, though whites are only a plurality, not a majority.

Prospects:

Democrats: The strength of unions, and the implicit class division between coastal and inland areas, favor Sanders slightly.

Sanders 4, Clinton 3

Republicans: Trump will do well here among white working-class voters, military voters, and even traditional conservatives.

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.