U.S. Sen. Mark Kirk (with cane) is flanked by Vice President Joe Biden and U.S. Sen. Dick Durbin and is assisted by fellow senator, Joseph Manchin of West Virginia, on his return to the Senate Thursday. | Natasha Korecki~Sun-Times Media

U.S. Sen. Mark Kirk pauses halfway up the steps of the Capitol Building on Thursday, Jan. 3, 2013. | Jon Sall~Sun-Times

IL Senator Mark Kirk (waving) is welcomed on the US Capitol steps by Vice President Joe Biden (far left) and W. Virginia Senator Joe Manchin (2nd from left) and many other Senators lining the steps on Thursday, Jan. 3, 2013. | Jon-Sall~Sun-Times

Illinois U.S. Senator Mark Kirk reaches the top of the U.S. Capitol steps on Thursday, January 3, 2013. | Jon Sall~Sun-Times

Illinois U.S. Senator Mark Kirk (waving) is welcomed on the U.S. Capitol steps by Vice President Joe Biden (far left) and West Virginia Senator Joe Manchin (2nd from left) and many other Senators lining the steps on Thursday morning January 3, 2013. | Jon Sall~Sun-Times

Illinois U.S. Senator Mark Kirk (waving) is welcomed on the Capitol steps by Vice President Joe Biden (far left) and West Virginia Senator Joe Manchin (3rd from left) and U.S. Senator Dick Durbin (2nd from rt), and many other Senators lining the Capitol steps on Thursday morning January 3, 2013. | Jon Sall~Sun-Times

Illinois U.S. Sen. Mark Kirk is helped up the Capitol steps by Vice President Joe Biden and West Virginia Sen. Joe Manchin as many other Senators line the Capitol steps Jan. 3. | Jon Sall~Sun-Times

US Vice President Joe Biden (L) greets Illinois Senator Mark Kirk upon his return to the Senate on January 3, 2013 after suffering a stroke last January.File Photo. AFP PHOTO/JEWEL SAMADJEWEL SAMAD/AFP/Getty Images