Rep. Lou Lang, D-Skokie, says the hearings are not a courtroom trial and accused Genson of trying to turn them into "a circus" with the requests, the Chicago Tribune reported Sunday.
U.S. Attorney Patrick Fitzgerald has asked lawmakers to not subpoena witnesses involved in his criminal case against Blagojevich, who is accused, among other things, of attempting to sell Obama's vacant U.S. Senate seat for political contributions and favors.
Genson is demanding the lawmakers subpoena Rahm Emanuel, Obama's incoming chief of staff, as well as longtime adviser Valerie Jarrett, saying Blagojevich can't get a fair impeachment hearing without them.
"This is a smoke screen," said Lang, whose committee will meet again Monday. "He's asking for subpoenas of witnesses he knows the U.S. attorney does not want us to have, and I, for one, am not going to allow him to turn this into a circus or sideshow."