The decade of war has changed the military's (current and former) political ideology a bit. (former includes contractors)
The number of independent/non-affiliated servicemen/women is on the rise: http://www.armytimes.com/news/2010/04/military_poll_advance_041110w/
My personal experience is that many people who become disenfranchised from the GOP have gravitated towards Libertarianism or taken a more moderate stance (think Romney/McCain). Ron Paul becomes the closest feasible Libertarian option. Some of the moderates support President Obama since his counterterrorism policies are leaning towards Special Ops and drones which puts less troops in harm's way; even conservative military personnel don't disagree too much with this CT stance.
"I hate war as only a soldier who has lived it can, only as one who has seen its brutality, its futility, its stupidity." -Dwight D. Eisenhower