WI by January 65 Democrat President Johnson or Kennedy or Humphrey of McCormack decided on no more bombing and no ground troops.
1) How long would South Vietnam survive?
2) Assuming it has fallen how much of an issue would the 'loss' of South Vietnam be in the 1968 election?
While my spirit lies with the general uprising line that represented the revolution in the south, the actuality was that the general offensive (Giap) line was correct. However, by 1965 the Giap line was out of favour. We can see this up to 1968 where he gets returned to clean up the mess of Tet.
Here is gets messy. In 1964 the NFL's PLAF were countering and turning back ARVN actions including well "advised" actions. This means that the NFL may be precipitate above and beyond the War line of the VWP. A 1966 NFL general uprising is likely on VWP orders without US intervention. This probably succeeds with regular (ie: provincial) PLAF forces acting as the General Offensive segment. The collapse of the ARVN and RVN government is more or less complete.
Then there's a massive problem for the VWP, because a revolution won in the south.
By November 1968 who is going to care in Omaha?
yours,
Sam R.