46Driver,
The Vietnam war taught us how effective a low-tech machine can be at close air support, and that jump-started the A-10. The most effective bomber for CAS was the A-1E, which carried several tons, went in slow and could hit the target, in spite of its big radial engine and oil-soaked windshield. Most fast-movers were more capable of area targets and less effective that the A-1, IMHO (I directed the CAS for a bunch of different type arcraft as a Cav pilot).
The Cheyenne was very long on
PR and short on delivery of the goods. It didn't get defeated by politics, it left a few too many smoking holes.
here is a site that gets the program history right:
http://www.aiaa.org/tc/vstol/augmented.html