And it was "politics" that spent 1% of GNP for a couple of years on Apollo in the first place. Who exactly was going to pony up the funding for a crash manned Mars program that "politics" then thwarted.

We went to the Moon because of the Cold War. Full Stop.

No science, no spacefaring, no Buck Rogers, but POLITICS, pure and simple. That's what put men on the Moon.

There was no Cold War or other compellling political reason to go to Mars.

I'd be very interested to see any evidence that some group was willing to finance such a program, or that the public was clamoring for one to be funded, but was stopped due to "politics".

Unless by politics you mean the inconvenient fact that the overwhelming majority of the U.S. public and their elected representatives were uninterested in an expensive manned Mars program in the 1970s, and therefore did not spend the public funds in the way you would have preferred.