Is Clinton-Obama Unity Just a Town in N.H.?

"Small donors who are writing $5 or $10 or $15, $25 checks -- first of all, their budgets are tighter," Obama said. "I'm not going to be individually contacting $15 donors, because, frankly, it probably wouldn't be that effective in terms of making a big dent in Sen. Clinton's debt."

Sens. Barack Obama, left, and Hillary Clinton are working hard to show that the bitter disputes of the Democratic presidential nomination fight are behind them.

(Reuters/AP Photo )

Another challenge in uniting the two campaigns is getting Bill Clinton, whose public comments about Obama have been tepid, on board. The former president was irked during the primaries by insinuations he had used racially charged language about Obama, and by Obama's occasional belittling of his accomplishments.

"I don't think Bill Clinton had that closeness, that up-front closeness, to Barack Obama that Hillary had, and that makes it a little more difficult," Pennsylvania Gov. Ed Rendell, a former Clinton supporter, told ABC News.

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Rendell said that, to Bill Clinton, "Barack Obama was sort of a stand-offish figure," while, to his wife, he "was someone she worked with, someone she likes, someone she respects and somebody she stood toe-to-toe with. She knows how good Barack Obama was, just like he knows how good she was."

Rangel said Bill Clinton might have gone too far sometimes, but that should be understandable.

"I've seen some awkwardness and some flare-ups that I know should not have occurred," Rangel said, adding that these flare-ups would not have occurred if the Obama campaign hadn't been "messing with the man's wife."

Obama today downplayed any tension with the former president, saying Bill Clinton's terse words of support for him, so far, would not affect party unity, "because I'm going to be appearing with Sen. Clinton, the former president's wife, who was involved in an epic, historic primary with me."

He added that "if the question is, do I want Bill Clinton campaigning for us, for the ticket, leading into November, the answer is absolutely yes. I want him involved. He is a brilliant politician. He was an outstanding president. And so, I want his help, not only in campaigning, but also in governing. And I'm confident that I'll get that help."