"We have come to the end of an exciting primary and caucus process –- the voters have spoken ... Democrats must now turn our full attention to the general election," read a joint statement released by Senate Majority Leader Harry Reid, House Speaker Nancy Pelosi, DNC Chair Gov. Howard Dean, and Democratic Governors Association Chair Gov. Joe Manchin. The Democratic party leaders urged all remaining uncommitted superdelegates to make their decision known by this Friday.
However, Clinton may be trying to leverage her support for a place on the ticket as Obama's running mate.
Speaking on a conference call to fellow New York lawmakers earlier today, Clinton said she is "open" to being Obama's vice presidential candidate if he asks, a source on the call told ABC News' Rick Klein.
Late tonight, Lanny Davis, a long-time friend of Clinton's, circulated a petition asking Obama to choose Clinton as his running mate.
The win is a huge accomplishment for Obama, 46, a first-term U.S. senator, who would be among the youngest presidents in U.S. history if he wins the White House.
With a popular campaign message of hope and change, he attracted huge crowds, celebrity endorsements, and record-breaking campaign contributions. His candidacy also inspired a record turnout by black voters, and enjoyed wide support from independents, liberals, young voters, and high-income Democrats.
Early on, Obama cast his campaign as a rejection of old-style Washington politics, and painted Clinton as an incumbent.
Standing on the same stage where Sen. John McCain, R-Ariz., will accept the Republican Party's presidential nomination in September, Obama quickly pivoted to the general election, taking a swipe at his Republican opponent.
"John McCain has spent a lot of time talking about trips to Iraq in the last few weeks, but maybe if he spent some time taking trips to the cities and towns that have been hardest hit by this economy -- cities in Michigan, and Ohio, and right here in Minnesota -- he'd understand the kind of change that people are looking for," Obama said.
"Change is a foreign policy that doesn't begin and end with a war that should've never been authorized and never been waged," Obama said. "It's time to refocus our efforts on al Qaeda's leadership and Afghanistan, and rally the world against the common threats of the 21st century -- terrorism and nuclear weapons; climate change and poverty; genocide and disease. That's what change is."
Launching the general election fight full-throttle, McCain fired a shot at Obama in a nationally televised speech made before Obama had declared victory.
"I have a few years on my opponent, so I am surprised that a young man has bought into so many failed ideas," McCain, 71, told supporters Tuesday night in Kenner, La.
"You will hear from my opponent's campaign in every speech, every interview, every press release, that I'm running for President Bush's third term," McCain said. "Why does Senator Obama believe it's so important to repeat that idea over and over again? Because he knows it's very difficult to get Americans to believe something they know is false.
"Both Senator Obama and I promise we will end Washington's stagnant, unproductive partisanship," McCain said. "But he hasn't been willing to make the tough calls, to challenge his party, to risk criticism from his supporters, to bring real change to Washington. I have."