Sen. Ben Nelson (D-Neb.) said that Senate Republicans haven't approached him about switching parties.

Nelson, a centrist Democrat who's sometimes frustrated his party, that he doesn't have any plans to join the GOP, and hasn't received any entreaties to do so anyway.

"They've never approached me, so I don't know how hard they're working," Nelson said on Nebraska's KFAB radio of Republicans' rumored efforts to convince him, Sen. Joe Lieberman (I-Conn.) and Sen.-elect Joe Manchin (D-W.Va.) to switch parties.

"I'm not looking to leave the party, and that's why the party hasn't left me," Nelson explained.

Republicans are poised to control 47 Senate seats (pending the outcome of Alaska's Senate race) over the next two years. They need 51 seats to retake the majority, since in the case of a split Senate, Vice President Joe Biden breaks a tie.

Nelson is also facing the prospect of a tough reelection race in 2012, and he rejected changing parties in order to find an easier path to victory. The state's Republican attorney general, Jon Bruning, has already expressed an interest in running.

"At this point in time I'm certainly planning to run. But I wouldn't do that just to keep the job," he said of a party switch. "My focus is not on just hanging onto this job forever."

The centrist did hope for compromise the next two years, though, expressing optimism that not all Senate Republicans would join with their leader, Sen. Mitch McConnell (R-Ky.), who's said his top priority is defeating President Obama in 2012.

"I think it's an interesting thing for a leader to say, but he's their leader, and if this is what his plan is, it's going to be very difficult to work together," Nelson said. "Now I'm still optimistic, because I don't think he speaks for everyone on that side of the aisle."