The door on Sen. Joe Lieberman (ID-Conn.) may be closing, slowly, as Democrats reassess their slim majority following the November elections.

“I got 60 votes, because of Joe Lieberman. We’ll get to it next, when we have to next year … I have a 51 [seat] majority,” Majority Leader Harry Reid (D-Nev.) said on Thursday, referring to the slim majority that Democrats hold in the Senate and a Wednesday evening vote on Medicare, in which Lieberman provided crucial backing to his Democratic colleagues in supporting the bill.

Reid insisted that he was not considering ousting Lieberman from his chairmanship atop the Homeland Security and Governmental Affairs Committee. However, he would not say what he would do if Democrats claimed a greater majority after the November elections in which Democrats are expected to pick up a significant number of seats.

Lieberman, who primarily votes with Democrats on most issues except for the Iraq War, has drawn serious ire lately for endorsing Sen. John McCain (R-Ariz.) in the presidential race instead of his Democratic colleague, Sen. Barack Obama (Ill.).

Lieberman has since toned down his criticism of Obama, mainly focusing on his support for McCain.

A petition delivered Tuesday to several Democratic lawmakers demanded Lieberman’s removal from the Democratic Conference.