"I am in the solutions business," she told more than 4,000 supporters in a packed fairgrounds here. "My opponent is in the promises business."
A day after suffering lopsided losses in Maryland, Virginia and the District of Columbia, Clinton acknowledged Obama's victories, but offered a taunt as well.
"I want to congratulate Senator Obama on his recent victories and tell him to meet me in Texas," she told reporters in McAllen. "We're ready."
It was bravado talk for a candidate whose campaign has been staggered by defeats since the Feb. 5 Super Tuesday contests, who is behind in fundraising and who has reshuffled her campaign staff. Clinton is now looking to be competitive in the Wisconsin primary on Tuesday and then prevail in Ohio and Texas on March 4.
Obama has been lavishing attention on the historically independent voters of Wisconsin. Clinton is moving belatedly to make a contest of next Tuesday's Democratic presidential primary. Obama, the junior senator from neighboring Illinois has spent more time in Wisconsin than the former first lady. He drew 4,000 people at a rally last October and beat Clinton back to Wisconsin this year.
Speaking before a crowd in Waukesha, Obama sounded like a man warming up for the general election, CBS News correspondent Dean Reynolds reports.
"If you want the same as we've had the last seven years, then I thinkn is going to be a great choice," he said.
At Janesville, he lumped both McCain and Clinton together in a derisive union.
"Politicians like John McCain and Hillary Clinton voted for a war in Iraq that should've never been authorized," he said.
But Clinton hasn't conceded the 74 delegates at stake in Wisconsin even though she has already begun campaigning for the larger delegate prizes offered in Texas and Ohio on March 4. Her advisers say the New York senator may not win Wisconsin but can't afford another of the lopsided defeats she suffered in three mid-Atlantic primaries Tuesday.
Clinton campaign advisers said Wednesday that her fundraising was rebounding after Obama outraised her 2-to-1 in January and predicted that her hunt for delegates to the national nominating convention would catch up to Obama on March 4 when Texas, Ohio, Rhode Island and Vermont vote. The Clinton camp is especially counting on victories in Ohio and Texas.
Her history in Texas, her institutional support among Democrats in the state and an affinity for the Clinton name among Hispanics, one of her most loyal voting blocs, all attest to her firewall strategy in the state.
But a complicated delegate selection system, Obama's momentum and erosion in Clinton's traditional support coalition could deny her the kind of decisive win in the state she needs to reverse her post-Feb. 5 slide.
"You go on," she said at a news conference. "Some weeks one of us is up and the other is down, and then we reverse it. ... It's a long and winding road."
Following his Tuesday victories, Obama now has a 66-delegate lead over Clinton - 1,251 to 1,185, according to the latest tally by CBS News.
Clinton needs strong performances in Texas and Ohio to close the gap with Obama. Obama campaign manager David Plouffe told reporters in a teleconference call that Clinton would have to win both states by more than 20 percentage points. "And we certainly don't see any evidence of that," he said.
Clinton political and field director Guy Cecil said that after March 4 he expected the race will be in a virtual tie, with the candidates within 25 delegates of each other.
He said the campaign is opening offices and hiring staff in all remaining states that are left to vote, from Wyoming to Montana, Mississippi to Pennsylvania, and even in Puerto Rico.
Clinton's stepped up criticism of Obama was part of a campaign strategy to challenge him directly on the economy and health care on a day when Obama proposed to spend $210 billion over 10 years to create jobs in construction and environmental industries.
"I have solutions to these economic challenges; the question today is does Senator Obama?" she said. "A plan that fails to provide universal health care, fails to address the housing crisis, and fails to immediately start creating good paying jobs in America again will not turn the economy around."