It is a move with a predetermined outcome designed to allow the democrats to say, "SEE! Karl Rove is ignoring the subpoena!", while they know damn good and well he has no other option but to deny the subpoena due to his previous position in the Bush administration.
This particular kind of dogshit politics is especially heinous and completely unfair to the public. The real dishonesty, the fact the democrats are trying to create a situation in order to create the illusion of lawlessness on the part of the administration in general and Karl Rove in particular, cheats the public out of the honest government we are entitled to for the sick political gain of a bunch of anti-American scum in congress.