Ummm, I'm not worried about liberal civilians. I'm worried about the Armed Forces of the United States who would be ordered to suppress insurrection and rebellion. There's something about helicopter gunships that gives me the willies... We just don't have the access to RPGs that the Iraqis do.
The US military is far more politically conservative than the average bear. If ordered to fire upon civilians in a nationwide uprising you'd see military folks defect in droves to the conservative side--this would be especially true of national guardsmen who would refuse federalization in big numbers.