Patriotism

My liberal friends are openly anti-war, opposed to nationalism, and loath the U.S. military, but they claim to be patriotic. There is even a lefty bumper sticker that says "Peace is patriotic." Since there is nothing illegal about publicly stating, "I am not patriotic," why pretend? Why don't they just admit they are not patriotic? Many liberal youth have the courage to refuse to say the pledge of allegiance, but everyone wants to be patriotic. I don't get it.