Only retail politics might work at this stage. If they contact 1,500 voters per day (via handshakes, phone calls, hugs, etc) with a success rate of 75%... that’s 2,463,750 new Republican voters in six years if my math is right. Probably enough to just barely eke out a win in CA-GOV 2026 if Newsom leaves office unpopular. It would be an narrow win tho, something like ND-SEN 2012.
A Better strategy is to hope Trump loses in 2020 , and the GOP moves away big time from Trumpism and the Democrats become anti-Big Tech. Once that happens the GOP might have a chance in 2026 if they nominate someone like Steve Faulconer . Even then the state wide GOP will have to be pretty independent from the National GOP
And this only applies to Gubernatorial elections and other statewide races relating to statewide politics , not the Senate races and certainly not the Presidential Race in California .