Like I said to qnetter: you may be right, but the consequences are very hard to swallow. Abandoning the option of impeachment entirely seems as though it means we are giving up on the very possibility of holding the president accountable for his crimes -- and that includes the warrantless wiretaps, holding prisoners without trial or counsel, and all of the other crimes you mention, which I agree are far far worse than the Libby commutation.

It's immensely difficult for me to see how refusing to impeach this president because we don't want impeachment to become a standard game honors the constitution. On the contrary, it seems as though it sends the president the message that he is above the law, after all.