Sen. Evan Bayh, D-Ind., former Sen. Sam Nunn, D-Ga., both from key states targeted by Obama's campaign, stumped with the likely Democratic presidential nominee in Bayh's home state, dancing around questions of a possible offer of a vice presidency during a news conference, the Chicago Tribune reported Thursday.

"Any questions about the vice presidential thing are understandable and it's good for my ego," said Bayh. "But I should probably let Senator Obama and his campaign address those kinds of questions."

Nunn, a former Senate Armed Services Committee chairman, said: "It's always nice to have your name mentioned. I would talk to Senator Obama, if he wanted to talk about it. But I think the chances of an offer are pretty slim. ... I'm not pining to go back into public office."

Nunn is an expert on foreign policy and military affairs, the Tribune said, areas polls indicate Obama is behind likely Republican presidential candidate Sen. John McCain of Arizona.