Gore!

Here's a copy of the speech. Quite good.

And a story on the speech here. ABC News actually spoke with Gore afterwards:

Asked by ABC News following his speech whether President Bush's domestic spying program constituted an impeachable offense, Gore said it might be and pointed to one of the three Articles of Impeachment that the House Judiciary Committee approved against President Nixon on July 27, 1974.

"That's a legal determination for the Congress to make," Gore told ABC News. "But Article II of the impeachment charges against President Nixon was warrantless wiretapping that the President said was 'necessary' for national security."

"It can be" an impeachable offense, he added.

The President can claim just about anything is "necessary" for national security. I'd argue that the following the rule of law is tops on that list.