If California was split into two states, would SC be a battleground state?

[Downnice]

Lets say California passes a referendum and California is split into 2 states Southern and Northern California, do you think Southern Cal would be a competive state.


Monterrey, San Benito, Fresno, and Inyo County and counties south of that would be Southern California and all counties north are Northern California.

Trump did poor in 2016 losing Orange, Riverside, and Fresno County, all counties won by Romney in 2012. Lets assume in 2016 Trump gains support being the incumbent and all those counties turn red and does what Bush did in California and Retakes San Diego, San Bernandio, Ventura and San Luis Opisdo counties, I think the GOP would win that state. However we need to take into consideration that the Latino vote is only going to get larger into California and that San Diego County has not went to the GOP since 04, but at the same time  I would presume the GOP in this scenario would campaign heavily in San Diego.

So if this were to happen in 2020 (it is %99.9 chance it does happen this is purely hypothetical) would Southern California be a battleground state, and how would it change the Electoral College?