I would suspect they are. It is a federal offense to even suggest a threat to a federal politician or candidate. I doubt, though, they would want that to be made public as to do so might trigger more such threats from sick $#@!s who only want attention.
But we are dealing with a president who has interfered with deportations of illegals and put a lid on an investigation of arms deals with Mexican drug lords by his own people.
that's what people don't get. Fast and Furious may be a simple, stupid but benign bit of idiocy, but if he can stop that, he can also see to it that these threats slide....
I would be interested in seeing what Obama has to say about it......