That is all he ever does - threatens. He threatened to block Sotomayor and Kagan and then voted for them. He's all hat and no cattle.
As we used to say in the Navy, "he has an alligator mouth and a humming bird *sshole.
There is danger from all men. The only maxim of a free government ought to be to trust no man living with power to endanger the public liberty.
Public virtue cannot exist in a nation without private, and public virtue is the only foundation of republics. There must be a positive passion for the public good, the public interest, honour, power and glory, established in the minds of the people, or there can be no republican government, nor any real liberty: and this public passion must be superior to all private passions. John Adams