Hubert Humphrey/Mike Mansfield (Democratic): 43.14% (298 Electoral votes)
Richard Nixon/Henry Cabot Lodge (Republican): 42.25% (164 Electoral votes)
Harry Byrd/John Stennis (States Rights): 13.22% (71 Electoral votes)
This feels about right, with the strong Dixiecrat movement offset by Humphrey victories in WI, IA, & other states in the Midwest. Perhaps this would even moreso be the case were Humphrey to have chosen a Southerner like LBJ as his running mate, as they'd likely serve to minimize any further defections among Southern Democrats.