I would agree that a non-partisan space plan is best for all. JFK was
able to sell that by inspiring the liberals with dreams and quelling
the conservatives with cold war rhetoric.

That worked for 1961-1962 (the conservatives which he most needed to
win over were conservative Democrats in the Senate - people of that
ideology would now be Republicans).

Later in the decade, getting Apollo through Congress was very hard.
JFK gave a number of public speeches about cooperating with the
Soviets in space, which lost him the Cold War angle. But then JFK was
shot, and that is perhaps what saved it.

The main source I could quickly find for this was the radio program
http://www.wamu.org/special/moon.html which might not be the best one
but which does seem to cover the basic material. The web site does
have transcripts.

Anyway, I was looking for answers about what saved Apollo from
cancellation. I didn't really find a particularly complete picture.