WASHINGTON - Rep. Pete DeFazio, D-Ore., officially joined a small but persistent group of Democrats Wednesday calling for a robust investigation into the tenure of Vice President Dick Cheney as a possible prelude to impeachment.

DeFazio agreed to sign a letter circulated by Rep. Bob Wexler of Florida who has been relentlessly driving the so-far unsuccessful effort to boot Cheney from office.

Wexler is backing his demands by orchestrating a petition drive aimed at showing public demand for investigating Cheney. The focal point of that effort is a website that allows anyone to sign the impeachment petition. So far he has 227,000 signatures.

``The charges against the vice president relate to the core actions of this Administration, its unlawful behavior and its abuse of power,'' Wexler wrote in a letter to House Judiciary Committee Chairman John Conyers.

``As you know, the charges against Vice President Cheney include providing Congress and the American people false intelligence leading up to the Iraq war, the revelation of the identity of a covert agent for political retaliation, and the illegal wiretapping of American citizens,'' says the letter, which was signed by Wexler, DeFazio and 13 other lawmakers.DeFazio, who has been a frequent critic of the administration, said he had remained largely on the sidelines of the impeachment debate until now because it was centered in the Judiciary Committee of which he is not a member.

But Wexler circulated the current letter more broadly, allowing members like DeFazio and opportunity to official voice their concerns.

Even so, DeFazio isn't quiet as absolute as Wexler, who has been calling for impeachment for months.

DeFazio said in an interview that he supports aggressive oversight hearings into questions surrounding Cheney's performance but is withholding calls for impeachment until a case is made. ``I have said I want to have the most aggressive oversight ... regarding malfeasance by this administration,'' DeFazio said.

``Cheney is the pivot point to the most nefarious practices of this administration.''

Despite Wexler's persistence and DeFazio's seniority, it is unlikely that House Speaker Nancy Pelosi will allow impeachment activities. She has said repeatedly and consistently that impeachment ``is off the table'' because it would get in the way of other priorities facing Congress.

-- Charles Pope