so no change from OTL..Democrats get hammered for 'losing' South Vietnam, for going back on JFK/LBJ's/the party's prior commitments on matter once Saigon falls in 66 or 67 or 68, that combined with widespread civil unrest in major urban areas, white backlash to civil rights, and George Wallace's 3rd party splinter gets you, more likely then not, a law and order Republican in 1968.