The GOP has been long affiliated with the military, and they use military propaganda as a political cudgel. This is incentive enough for someone to be a hypocrite, rather than merely "wrong."
For the polit clowns it is a reason to be a hypocrit but only if their are people believing it, for the general population not. Somebody has to believe it, so that the propaganda works. And AFAIK McCain has a son, who fought in Iraq and Palin has a son, who is soon to go to Iraq. That's untypical, I know, but a little bit of believe must be in them.

They are so proven wrong on Iraq
Yes, and telling, that one is against this war, or was against it from the beginning isn't something considered 'unpatriotic' anymore, or? Sure, the Republicans play the "Obama is for losing in Iraq" game, this may help to consolidate their most extremist base, but will hardly work to gather independents.
It did work in the run up of the war in 2002. Many say, the then recent memory of 9/11 has boosted that. For sure many Americans after 9/11 did think, the country needed a strong answer (~90% approval to Bush in the beginning of the Afghanistan war); was there a mass enlistment of middle class people with good job chances after 9/11?

If military service were truly "honored" then wouldn't those who favor militarism take care of the soldiers who come home wounded?
The polit clowns use it as propaganda, and they tell they would care well for the veterans. Low information voters might think McCain as a veteran himself will care more for the veterans than Obama.

Der Amerikaner ist die Orchidee unter den Menschen
Volker Pispers