I believe any objective reasoning regarding the issue will support the thesis. Bush is the President...he won the election with a majority of the voters...an election where this very issue was a big part of the decision.
Bush, as president, has taken us to war in Iraq and Afghanistan. The force fighting that war is made up of an all volunteer force. Those fighting have volunteered and are volunteering.
Erego...clearly the vast majority of that force must support the war and Bush else they would not volunteer. Ergo...the majority of their parents and spouses support the effort as well.
Parents and spouses have (in most cases) significant impact and influence on an individual's major life's decisions.
In the case of Casey Sheehan that was not true...as evidenced by his mother's spectacle. But I do not for an instant, based on objective reason, believe that her's is a majority position.
I don't believe her position is the majority either, but you can't just assume it is in a news article.
This article uses BOTH some and many to describe the number who oppose Sheehan.
That is good enough for me, and it is exactly what I would have done. I would never write "most" unless I have some statistics and polls of military families to back me up.