That's a threat?? THAT'S no threat!
A straight-up rendering in standard English reveals the unmistakable intent to imply that the inverse is actually the truth. Roughly: "The very reason, Mr. Arrogant Congressman, that your ass ISN'T going to be burnt on a cross on the White House front lawn, is NOT that we don't have hoods, but that we're NOT the kind of people your persistently-racist heart thinks we are. We are not guilty of racism; YOU are guilty of slander. We are not the haters; YOU are the hater. We don't need to go away; YOU do."
That's a threat?? THAT'S no threat!
My take on this "threat" was similar to yours. I would like to see the email in its entirety, as I suspect that the quote up top there is clipped, and there is more that we aren't seeing. Something like this:
"If our tea parties had hoods, we would burn your ass on a cross on the White House front lawn. We don't wear hoods, as your colleague in the Senate, Robert 'KKK' Byrd did; we aren't the KKK, he is. Proof of our peaceful nature is that your slimy ass is still alive. We do, however, plan to do everything in our power to unseat you in November."
At least one person here passed reading comprehension. You have it exactly right. I can’t believe how long it took someone to get it. Do so many people just fly off the handle without comprehending what is being said.