I guess that's because lots of them are veterans themselves, and lots of them have family and friends in the military, not because they're so terrifically fond of the oligarchy. I'm a contruction worker myself and I talk to these people every day, not just look at their bumper stickers.
If you look at the people who end up in the military these days, as I've been doing a lot lately while surveying for the new "antiterrorism gates" at the Air Force base in Tampa, you might notice they're practically all from that contruction-worker economic class.
The vets I work with are absolutely cynical about the motives of the ruling class. Ask them for what they went to Iraq and inhaled DU dust and oil-well smoke, and not a one of them will mention airy concepts like "freedom" - they invariably frown and snap out a one-word reply: "oil." Flagism on their part is mostly motivated by their desire to cheer for the guys in uniform.
Unfortunately lots of the Desert Storm generation favor right-wingers politically, not because they respect the transparently nonsensical official reasons those right-wingers give for sending U.S. soldiers into danger (believe it or not, construction workers aren't quite that stupid!) nor for the clearly-understood underlying reasons for these wars - they're aware that whatever megaprofits guys like VP Cheney and Army Secretary White make from invading Iraq, not a cent will ever trickle down to their class - but because they fear that any anti-war efforts will somehow undermine the war effort and thus get more of our soldiers killed. It's the Vietnam myth, "if it weren't for the Fifth Columnists at home, we'd have won fast and hard and most of those fifty-seven-thousand wouldn't have been killed."
Yours WDK - WKiernan at concentric.net