Obama answers questions on Wednesday aboard his campaign plane. "We still have an insurmountable lead," Obama said on The Early Show. "We're very confident about where we're going to be and that we can win the nomination and the general election."

Hillary Rodham Clinton, fresh off big primary victories, acknowledged Wednesday the possibility of sharing the Democratic presidential ticket with Barack Obama, with her at the top — a potential 'dream-ticket' scenario she and Obama first speculated about at a debate in January.
But Obama continued to play down his losses, stressing that he still holds the lead in number of delegates after losing the crucial states of Texas and Ohio to Clinton on Tuesday night.


POLITICS BLOG: A Clinton-Obama ticket?
PRIMARY HIGHLIGHTS: Miss the speeches? See highlights here

Meanwhile, in a Rose Garden ceremony at the White House Wednesday President Bush endorsed John McCain. "I want him to win," Bush said, adding that he will campaign for McCain and help him raise money.

McCain arrived at the White House with his wife, Cindy, shortly before noon to have lunch with Bush before the endorsement.

"He's a president -- and he's going to be the president who will bring determination to defeat an enemy and a heart big enough to love those who hurt." Bush said.

With the Republican nomination clinched the two Democratic rivals didn't waste any time Wednesday blasting away at each other on various issues.

On CNN's American Morning Obama renewed his line of attack on Clinton.

"The most important foreign policy call that she's had to make since being in public office," he said, was when it came time to vote to authorize actions against Iraq. "She made the wrong decision."


EXIT POLLS: See how voters made their decisions

His judgment about the war, Obama said, "has been superior."

Clinton appeared on the show soon after.

"Senator Obama's whole campaign is about one speech he gave in 2002," she said, dismissing his position that he showed the better judgment by opposing the war in Iraq before it ever began.


MCCAIN CLINCHES: Turns attention to November

Clinton and Obama made the round of morning talk shows Wednesday both insisting they had the best credentials to go head to head — or as Clinton put it "toe to toe" — against McCain.

Asked on CBS' The Early Show whether she and Obama should be on the same ticket, Clinton said: "That may be where this is headed, but of course we have to decide who is on the top of ticket. I think the people of Ohio very clearly said that it should be me."

Obama, who had hoped to knock Clinton out on Tuesday, said he would prevail against a tenacious candidate who "just keeps on ticking."

"We still have an insurmountable lead," Obama said on the Early Show. "We're very confident about where we're going to be and that we can win the nomination and the general election."

Even though Clinton won in Texas, Ohio and Rhode Island — with Obama taking Vermont — she's still behind in the delegate count.

Late returns showed Clinton emerged from Rhode Island, Vermont, Texas and Ohio with a gain of 12 delegates, with another dozen yet to be awarded, according to the Associated Press' count.

That left Obama with an overall lead of 101 delegates, 1,562-1,461 as the rivals look ahead to the final dozen contests on the calendar. It takes 2,025 to win the nomination.

Getting to the 2,025-mark necessary to win the Democratic presidential nomination is a next-to-impossible task for her, even after Tuesday's victories, say those who have studied the numbers.

"Even if she wins every contest left, Clinton still would have a hard time overcoming Barack Obama's pledged delegate lead," according to the AP. "In fact, her task got even harder because even though she won Texas, Ohio and Rhode Island Tuesday night, she didn't do much to close the delegate gap — and with every contest that passes, the number up for grabs drops."

Clinton has the support of 241 superdelegates, and Obama 202. But more than 350 remain uncommitted, a large enough bloc to swing the nomination should they band together.

Clinton acknowledged Wednesday the race was close and said it would come down to her credentials on national security and the economy.

She told FOX Wednesday that she believes she won Tuesday's states because people are starting to asking themselves who can be commander in chief, turn the economy around and go after some of the big issues that people are concerned about, like health care and rising gas prices.

"The more those questions are asked and the campaigns are really focused on what we need to do to win the general election and then, you know, have a Democratic president who's going to turn the country around, the better that is for me," she said.

Of McCain, Clinton said he will be a "formidable opponent" who will bring "quite extensive national security