"Affinity group voting is a real thing in this country," said Gary Langer, ABC News' director of polling. "People tend to vote for someone with some common shared experience that is important to them. To the extent John McCain is a celebrated war veteran and can use that to appeal to veterans, he certainly will, and hope that it works."
In South Carolina, which is home to an estimated 400,000 veterans, McCain beat former Arkansas Gov. Mike Huckabee, 34 percent to 26 percent. He lost to Huckabee among non-vets by 29 percent to 26 percent. In Michigan, McCain beat former Massachusetts Gov. Mitt Romney, among veterans 41 percent to 32 percent. He lost to Romney among non-vets, 38 percent to 28 percent.
But Langer and other political analysts say it may be a mistake to look at the military vote as monolithic, in terms of party allegiance, support for the war in Iraq, or what issues are most important to them.
"One thing I think that's been a myth, is that military families only care about Iraq, and every other issue doesn't matter as much," said ABC News political consultant Matthew Dowd. "As we've seen the economy rise across the country [as a concern], the economy is now a big issue among families, as big an issue as anything."
Dowd said veterans have become less Republican since 2000, when they voted overwhelmingly for President Bush. And, just as it has occurred among the general citizenry, many people with military backgrounds or allegiance, have turned against the war in Iraq.
"I think he has put himself in a difficult position, relating to Iraq because ... I think there is a significant growing portion of veterans and military families who disapprove of what's going on in Iraq, and he's been so strong on that, I believe at some point, they're going to start moving away from him," he said.
Langer said, even when appealing to veterans, it may be unwise to ignore stress support for the war, over addressing economic worries.
"When the economy goes bad, there's usually not much oxygen in the room for other issues," he said.
ABC News' Bret Hovell contributed to this report.