WASHINGTON (CNN) -- The Senate Judiciary Committee Wednesday authorized its committee chairman to subpoena White House Political Director Sara Taylor as part of the investigation into the firing of eight U.S. attorneys.

Chairman Patrick Leahy, D-Vermont, said he and the ranking Republican member, Arlen Specter of Pennsylvania, had sent a letter to Taylor two weeks ago inviting her to testify voluntarily but had received no response.

Referring to a possible subpoena for Taylor, Leahy commented, "This may focus their attention."

White House political staff were included in discussions and e-mails about the plan to fire the eight prosecutors. Taylor works closely with top Bush adviser Karl Rove. Both the Senate and House Judiciary committees want to learn details about the involvement of White House staff---especially Rove-- in the decision to fire the U.S. attorneys.

Leahy expressed concerns again today those decisions were made for political reasons and said politics should not touch the operations of U.S. Attorneys.

"The Department of Justice has to be worthy of its name," said Leahy. "It's there for all Americans. It is not there for one political party or another and they seem to have lost their way. It's the one department that cannot be a political arm of the White House."

Thus far the White House and Congress have not reached an agreement that would provide for White House officials to testify voluntarily.