Secession or Civil War are the only ways forward. If Trump really is out (which is likely even though it's not what we want to hear) then the only way forward is one of those two options. Either will weaken the country (which the democrats have already done) but it's what's necessary for the Republic to heal.

Red states that secede will likely end up keeping at least a good portion of the bases, equipment and personnel they have since their taxes helped pay for it and will form their own union that will be plenty strong. Secession hurts the blue states more and honestly, fuck 'em. They get what they voted for. Believe me, without hardworking conservatives to leech off of, a socialist union of former blue states won't last very long and will eventually collapse like every communist regime does.