If you've read Michelle Malkin's book Unhinged: Exposing Democrats Gone Wild, she specifically warned that there are many on the Left that are not above doing something insane like assassinating President Bush. If they even try that the FBI and Secret Service will come down HARD on most Leftist groups in no time flat.
I get so sick of reading what will happen if the left or some foreign enemy does something outrageous. When the country is enfeebled by the leftists, it will do relative squat.