I assume you passed it along to see what I would say :) The Chicks were pandering to an audience which felt the same way they did. Not very bright because they forgot that their audience back home would resent it. Oops. The concept of destroying CD's you've already bought is the lamest thing ever, but if it makes someone feel good, it's pretty harmless.
The most interesting thing here is that the writer refers to the occupant of the White House as Commander-in-chief three times, but never as "the President". This is a very modern concept. The framers of the constitution were all classical scholars, they understood that there was a constant tension between the military and the political class. The rise of the Caesars in Rome at the expense of the Senate was something they feared, so they made the President the commander-in-chief of the military, placing him above the generals. They were equally afraid of the President starting wars to aggrandize his power, so they gave the sole power to declare war to the Congress -- the representatives of the people.
In the latter part of the 20th century the power to control the military has been used to supersede the war powers of Congress and this is, frankly, a bit dangerous. The constant referral to the President as Commander-in-chief takes this one step further, cloaking the political officer in the mantle of the military during wartime, making criticism of the President criticism of the military. This is completely antithetical to the intent of the framers.
It is also completely out of step with 200 years of American history. FDR was never referred to by that title, JFK, LBJ, and Nixon never were. Even Bush I wasn't during the first Gulf War. But now this has become prevalent (and noticeably so outside the military where it might be expected) and I find that a bit frightening.
During WWII there was much criticism of FDR. During WWI, Woodrow Wilson was a controversial figure, as was his conduct of the war -- Teddy Roosevelt, hardly a peacenik, criticized Wilson everywhere he could during WWI. This was doable because he was criticizing not our soldiers and their leadership, but the political leadership, which is always acceptable in a democracy.
Back to the Dixie Chicks -- I too am embarassed by having Dubya as President (as many of you were by having Slick Willie as President). I think most of his policies are wrong and hope that Congress is not cowed by the mantle of Commander-in-chief.
But I support our troops and hope this war ends quickly and with minimal loss of American, British, and allied lives, as well as minimal suffering by the long-suffering Iraqi people. I also pray that in this case, the President and his people have it right and that winning this war is a step towards peace, not away from it. I'm guessing the Dixie Chicks feel the same way and it doesn't make either of us un-American.