I also question whether Congress will do a single thing if their subpoenas are ignored in this case. The whole Congress seems incompetent and unconcerned.
Yep, Congress is dropping the ball.
If that's the case, I will never vote for a Republican for Congress again. My intial thought was that the issuing of these subpoenas was an unconstitutional abuse of federal power. That being said, they still have the force of law until challenged. These subpoenas have never been challenged in a court. They cannot be disregarded. If they are, good luck getting Mark McGwire to show up before Congress again.
The rule of law in this country is a mess.