Campaigning as an outsider, Obama, who was elected to the Senate three years ago, acknowledged Tuesday that some of his proposals aren't that different from those of rival candidates. The difference is that the others have had years to turn plans into action.
"I know change makes for good campaign rhetoric, but when these same people had the chance to make change happen, they didn't lead," Obama said at a campaign stop in New Hampshire.
A day earlier, he outlined an environmental plan that includes some goals included in other candidates' plans, and he acknowledged on Tuesday his health care plan is similar to top rivals' thoughts on the subject.
"I would not be running for president if I did not believe this time could be different, not because I have some perfect solution that every other expert and every other candidate has somehow missed, but because I believe the American people are ready for a president who can unite us around a common purpose," Obama said.
Obama, a first-term senator from Illinois, is in a tight race against Sen.and former Sen. in polls and fundraising. He did not name them but said current leaders in Washington have failed - a charge that earned him applause among the mostly Democratic-leaning crowd.
"That's why America isn't leading when taking on the threat of climate change. Washington's failure is the failure of a president who has spent most of his time in office denying the very existence of global warming, suggesting that it might be a hoax," Obama said.
On one specific energy matter that is important to many in New Hampshire, he would not pledge to stop all new nuclear power plants.
"When you're a politician, you're always tempted to get some applause, but on this one I have to be more qualified," Obama said.
"We shouldn't simply remove nuclear power from the equation," Obama said. "But there has to be a high standard and a high threshold. ... I'm not going to automatically rule it out as a reasonable option."
On another topic - foreign trade deals, which are especially important to labor and U.S. manufacturers - Obama took tough questions from one voter who opposes an upcoming free trade bill that would add Peru as a trading partner.
Obama, who voted against the recent Central American Free Trade Agreement, said he would support Peru's inclusion because trade is a key way to keep the United States competitive.
"We're not going to draw a moat around the United States' economy," he said. "If we do that, then China is still trading, India is still going to be trading."