READ THE EXIT POLLS! John McCain had HIGH marks in the South Carolina Primaries! People liked him then and like him now (probably more then than now). 98% of the people who thought military service was their # 1 quality to look for in a candidate backed McCain.
McCain lost South Carolina because his # 1 issue was campaign finance reform, which NOBODY EVER CARED ABOUT, then or now.
Bush's # 1 issue was Tax Cuts, which EVERYONE cared about, especially in the 2000 GOP primary.
That was the end of his campaign.
It was also in South Carolina that some veterans spoke up about him abandoning the POWs from Viet Nam.
His reaction at that time was similar to what Kerry is doing now. Screeching, screaming, and blaming Governor Bush. He intimidated those vets, but that is not going to work this time.