If you've paid any attention to the gun control debate, you know the argument. Conservatives say the 2nd Amendment guarantees your right to bear arms so that you can defend yourself, your property, your family and other innocents against attacks from criminals or your own government. Democrats look at them like they're idiots and say something along the lines of "well, then why aren't there any examples of 'good guys with guns' stopping crimes?"
The conservative then points out that there are thousands of examples, and the Democrat changes the subject or moves the goal posts. In an apparent post-60's about face, they argue that only their former boogeymen - police officers and military members - should have firearms.