Silver replied that Obama could have won the general election without the Internet but might not have beat Hillary Clinton in the Democratic party primary.

"In the general election, the GOP had an unpopular president. People were fed up with Bush and his policies," Silver said. "The primaries were more interesting. Obama barely won."

Sifry agreed. "It was a tight primary, and Obama won with volunteer groups who won caucuses."

Silver said that the Democratic party retains an online advantage with such Web sites as Act Blue, which he called a "DIY PAC" because anyone can use the site to get groups to contribute to specific candidates.

At the conference, Act Blue unveiled software that allows people to donate to candidates through Twitter and receive a thank you tweet.

Democratic party should fear overconfidence

"The Democrats should not be too confident," Silver warned. "Obama is facing many problems and he made a lot of campaign promises."

On the other hand, the GOP is still in crisis. "People don't like their own party. The GOP is angry. There will be interesting primary challenges. In Florida, for example, Charlie Crist will face a conservative primary challenger," Silver said.

But the economy is an ongoing problem for Obama. "Obama is rated on a curve that gets steeper every day," Silver said. He added that most voters don't expect him to solve the economic problems today, but that about half of them expect the economy to be better by mid-term elections in 2010.

Silver said that if the 2008 Presidential election were re-run today, Obama would win more. He claimed that thanks to mortality rates, McCain loses 15,000 votes per day, and that due to the Democratic youth majority, the Obama vote grows each day.

However, according to the U.S. Census Bureau, there were 53,972,452 people aged 60 or over on July 1, 2008, the most recent date for which estimates are available. Silver's estimate may be high as it assumes a death rate of 10 percent per year among GOP voters, but even if the actual number is a third or one fifth of Silver's off-the-cuff number, it's still bad news for the GOP.

Asked when the world would recognize the need for action on climate change, Silver replied, "pray for warm weather. Last year was not as warm as in the early 2000s. There will be action when eventually it's 108 degrees in Boston in May."