For the second time in a month, a Senate committee will hold a hearing to explore the role of "czars" in the executive branch.

Sen. Joe Lieberman (I-Conn.) will convene the Senate Homeland Security and Government Affairs Committee on Thursday to explore "The Past, Present, and Future of Policy Czars."

That description is similar to the Senate Judiciary Committee hearings on czars a few weeks ago, titled "Examining the History and Legality of Executive Branch Czars."

Republicans and a handful of Democrats have questioned the administration's use of so-called czars, many of whom do not require Senate confirmation. White House supporters point out that previous presidents, including Republicans, have appointed similar advisers.

Witnesses at Lieberman's hearing will include former Homeland Security Secretary Tom Ridge, George Mason University Professor James Piffner, Attorney Lee A. Casey, and Harold Relyea, a former researcher at the Congressional Research Service.

The hearing is scheduled for the morning of Oct. 22.