This should dispel the myth that all veterans/military-types are Republicans:

Lawyer Patrick Murphy and five other veterans of the Iraq war are asking questions about President Bush's policies in Iraq as part of their broader Democratic campaigns to win congressional seats in next year's elections.

Given their experience in Iraq, the six Democrats in Pennsylvania, North Carolina, Maryland and Virginia say they are eminently qualified to pose the tough questions. Their reservations mirror public opinion, with an increasing number of Americans expressing concern about the mission and favoring a timetable for withdrawal of U.S. troops.

[snip]

The Democratic veterans walk a fine line as they reach out to voters who may question Bush's handling of the conflict. The task is to challenge the administration while still being seen as patriotic. (emphasis mine)

How more patriotic can you be than serving in the military? The Republican Smear Machine loves to trash liberals/Democrats as unsupportive of the troops, yet they are first in line to tar the character of any soldier that disagrees with their imperialistic view of foreign policy.

Recent victims include: John Kerry, Max Cleland and Paul Hackett

It's shameful but they do it because they know that it will win elections to drag their opponent through the mud. They love to play to the worst emotions in people, it is classic Karl Rove.