Actually it is pretty obvious:

Despite the fact that the media slams McCain every chance it gets.

Could the reason they dont attack his patriotism be due to the fact that his reputation and track record in that reguard is impecable,?

I mean he actually has fought and suffered for the American people.

Where as Obama's patriatism has been called into question since the begining by so many people that the media had to address it. Which is no surprise considering the company he keeps and his background. Basically Obama needs to wear the pin and began to do so after it was pointed out to him the need for him to do so.

It is of course a matter of perspective. The media is well aware where they can get thier jibes in and have the people swallow them and where they cannot.

A better question might be why does Obama have his own tv channel for his campaign?