Democrats ridiculed John McCain Sunday as a "clone" of President George W. Bush, as the battle lines of a November face-off between the hawkish Republican candidate and Barack Obama took shape.
But Hillary Clinton was adamant she was still in the Democratic nominating race, even with party leaders coalescing behind Obama after a gruelling primary season and now eager to take on McCain.
Senate Majority Leader Harry Reid, who has remained neutral in the nominating epic, gave a pithy outline of the Democrats' three main thrusts of attack against the Arizona senator.
"He's wrong on the (Iraq) war. He's wrong on the economy. He's a clone of George Bush," Reid told ABC, while urging Democrats to "relax" and let the Obama-Clinton battle play out until the final primaries on June 3.
Following Obama's victory in North Carolina last week, and his narrow loss in Indiana, Obama's chief strategist David Axelrod said on Fox News Sunday: "We're coming to the end of the process.
"And I think there's an eagerness on the part of the party leadership and activists across the country to get on with the general election campaign," he said.
"Senator McCain's been out there campaigning as the nominee for some time, and I think people are eager to engage," Axelrod said.
With Obama seeking to build up irresistible momentum against Clinton , the Democrats' camps denied they were in talks to end their White House race through a deal to cancel Clinton's campaign debts or on the vice presidency.
On NBC, Clinton's national campaign chairman Terry McAuliffe acknowledged that "something big would have to happen" for the New York senator to beat Obama to the nomination.
But he added: "We're not going anywhere. There have been no discussions with any other campaign about helping. Some of these stories I can unequivocally tell you here today ... are not true."
Clinton aides also denied that the candidate last week had played the race card against the African-American Obama when arguing that his support among "hard-working Americans, white Americans" was ebbing.
Heading into Tuesday's West Virginia primary, Obama has for the first time pulled ahead of Clinton in support from the superdelegates, who look set to crown the party's champion against McCain.
At least six more of the party grandees declared for Obama at the weekend, taking his count on the RealClearPolitics website to 275 to Clinton's 271. He also has 1,591 pledged delegates to her 1,426, according to its tally.
A total of 2,025 delegates is needed for victory, meaning the superdelegates will play a pivotal role at the Democrats' August nominating convention unless Clinton bows out first.
With the general election in mind, the Obama campaign on Saturday launched a 50-state voter registration drive whose co-chairs include actress Kerry Washington and singers Dave Matthews and Melissa Etheridge.
Sunday's New York Times reported that both McCain and Obama were gearing up for November by mobilizing in key swing states, targeting independent voters and readying attack ads to broadcast as soon as the Democratic race is over.
The report noted that McCain wants to organize "town-hall" meetings with Obama, so that the rivals can face voters directly without the mediation of TV debate moderators.
"We take that as a serious idea," Axelrod said on Fox.
"We're at war. Our economy is in turmoil. And we've got so many challenges that the people of this country deserve a serious discourse, and it shouldn't be limited necessarily to three kinds of very regimented debates in the fall."
Obama has sometimes struggled in televised debates with Clinton, and McCain will hammer his core message that the freshman Illinois senator is a dangerous risk for US national security.
Senator Joseph Lieberman, a Democrat-turned-independent and strident McCain backer, told CNN, "I worry that Senator Obama has not had that experience and therefore, ultimately, will compromise our security in that way and also our alliances."
© 2008 Agence France Presse. All rights reserved.