Some folks here are confusing McCain and Kerry and pretending there's a nonexistent equivalence. While I did think Kerry was the best of the Democratic choices in 2004 (which is hardly saying anything at all), but let's understand a few differences here:
1) McCain DID NOT campaign as "a war hero" in 2000 or for that matter 2008; Kerry DID in 2004.
McCain, in fact, was more upset and confessed to his own personal "weakness" under torture. He never tried to suggest that he was the Second Coming of Teddy Roosevelt or Useless S Grant or Eisenhower. Kerry, on the other hand, said "Vietnam" so often that I honestly thought it was his middle name. My goodness, when he showed up to address the Convention that night he barked, "John Kerry reporting for duty." So there was a complete difference in how these two guys handled their military service and it's the next thing that caused Kerry even bigger problems....
2) Kerry REFUSED to release his military records
Kerry's records
were not released until June 2005. Had he released these in 2003 - before the campaign got hot - then I seriously doubt the Swift Boat thing would have ever gained traction. (I also think - to be quite frank about it - that the Swift Boat thing was so minor in the larger picture that it was one more mark against Kerry but it did not determine the election).
The problem, though, is that Kerry was running as a "war hero" but for some reason came across as having something to hide about his military service. This left him vulnerable to "well we served with him and he wasn't any good at all and certainly not a hero." (I'm also amused by how many Democrats tried this argument but conveniently ignored it when it came to Bush in 92 and Dole in 96 against a Draft dodger).
There is simply no comparison of the two. About the only thing they have in common is that both are politicians who ran for President who served in the Navy during the Vietnam War. One was a POW for five years and the other came home and turned AGAINST the war and then tried to turn back and campaign as a war hero. Kerry was hurt far more by his slithery position than by anything the Swift Boat Vets did to him.
And btw - being a POW does not give you immunity from the positions you take in Congress. Jeremiah Denton was undone by his reputation for forgetting the home folks when he got to Washington and another remark that suggested he had not exactly evolved on women's rights.