Check out this commentary "Unwarranted Executive Power" by
Thomas G. Donlan found in Barron's Online

The caption below that article's title reads "The pursuit of terrorism does not authorize the president to make up new laws."

Here's an excerpt from that article:

"...Willful disregard of a law is potentially an impeachable offense. It is at least as impeachable as having a sexual escapade under the Oval Office desk and lying about it later. The members of the House Judiciary Committee who staged the impeachment of President Clinton ought to be as outraged at this situation. They ought to investigate it, consider it carefully and report either a bill that would change the wiretap laws to suit the president or a bill of impeachment.

It is important to be clear that an impeachment case, if it comes to that, would not be about wiretapping, or about a possible Constitutional right not to be wiretapped. It would be about the power of Congress to set wiretapping rules by law, and it is about the obligation of the president to follow the rules in the Acts that he and his predecessors signed into law..."

-snip-

BTW: Barron's is published by the conservative Wall Street Journal.
So it's not only liberals who are suggesting that Bush be subject to impeachment hearings.

You can read the entire article by clicking on the hyperlink provided.