(1) Seal the California borders.(2) GIVE California to Mexico.
(3) If Mexico won't take it--declare war and force Mexico to take it.
That is a better plan except for one small detail. If the U.S. declares war on Mexico......they’ll immediately surrender and then demand we rebuild Mexico for them. Hows about:
3) If Mexico won’t take it; trade California to China in exchange for extinguishment of the outstanding U.S. treasury bonds owned by China AND a 10 year commitment they’ll do daily live Reality TV Show broadcasts from their forced labor camps!