Neither Obama nor Clinton ever served, and the later pulled all kinds of strings and tricks to avoid service.
Kerry's service record is suspect, to say the least.
The fact he has one puts him a cut above Clinton, Obama, Cheney, and Bush.
And this has nothing to do with Partisan Politics, but has anyone noticed that at some point it actually became a liability to have a military record and run for President? Dole (Vet) got trounced by Clinton(draft dodger), Gore (Vietnam Vet) lost to Bush, Bush beat Kerry (Vietnam Vet), and Obama beat McCain (Vietnam Vet).
The only really partisan thing related to military service I've seen was the extent that Republicans will go to outright taint a Democrat's time of service. I didn't see McCain's time actually come up as an issue by anyone and Clinton never used Dole's time against him.