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-37: This middle class West Los Angeles district, including parts of South Central L.A. is a reliable liberal stronghold, represented by liberal Democrat Karen Bass. There are fewer than 40,000 registered Republicans in the area, and more than six times as many Democrats. Yet there is anecdotal evidence of the Cruz campaign already canvassing in the area — a sign of how organized it is, and how urban districts might prove decisive in the state.

Prospects:

Democrats: This is an important opportunity for Sanders, who enjoys wide support in the area, to rack up delegates.

Sanders 5, Clinton 2

Republicans: Cruz’s campaigning in the district is admirable, but probably not enough to overcome Trump’s support.

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.