MILWAUKEE - Barack Obama decisively won his ninth straight victory over Hillary Clinton in yesterday's Wisconsin primary, building an imposing delegate lead and extending a broad reach across Democratic constituencies, including many - such as women, lower-income families, and union households - that had been strongholds for Clinton in previous contests.
Obama's victory - he led 58 percent to 41 percent with 85 percent of the precincts reporting - was quickly answered with attacks from opponents in both parties. John McCain, who declared that he will be the Republican nominee after beating Mike Huckabee in Wisconsin, dismissed Obama's message as "an eloquent but empty call for change," while Clinton launched her most aggressive critique yet on his preparedness for the presidency.
"One of us is ready to be commander in chief in a dangerous world," Clinton said at a rambunctious rally in Youngstown, Ohio.
Obama's victory occurred despite the growing prominence in recent days of economic concerns that the Clinton campaign had considered among her strengths. Despite the change in focus, Obama broke into Clinton's support among lower-income white voters, who are predominant in Wisconsin's electorate, while he maintained a hold on young, independent, and African-American voters. He enters key primaries on March 4 with a sturdy base among all sorts of Democrats.
"Now people are beyond the mystique of who he is and are able to embrace all he has to offer," Willie L. Hines Jr., president of the Milwaukee Common Council, its citywide legislature, said of Obama.
Obama extended his lead in delegates with 1,316 to Clinton's 1,241, according to an Associated Press count that includes partial returns from last night, plus "superdelegates" who have committed to one of the candidates. He was also expected to win the caucuses last night in Hawaii, where he grew up, with another 20 delegates up for grabs.
Another overwhelming Obama victory increases the pressure for Clinton to win in delegate-rich Ohio and Texas on March 4. After appearing to transcend class differences that had split the Democratic electorate in earlier primaries, Obama's new demographic reach leaves him strongly positioned to compete in Ohio, which like Wisconsin has significant concentrations of working-class whites aggrieved by economic change, though also a greater population of the black voters who have been a reliable base of Obama's support.
Obama appears to be even with Clinton in the polls in Texas, and he told supporters at a rally in a Houston arena, "The change we seek is still months and miles away, and we need the good people of Texas to help us get there."
When it became apparent that Clinton was not going to make the customary acknowledgment of Obama's victory in her speech, Obama began his own address before she finished, in effect grabbing the national television spotlight from her and cutting her off midstride. Those breaks from the usual campaign etiquette reflected the tension between the two camps in recent days.
Before the Wisconsin contest, both campaigns - in an effort to lower expectations - tried to portray the state as a hotbed for the other's style of politics. Clinton's campaign identified the state's progressive tradition as fertile ground for Obama's appeals to reform-minded liberals. Obama's camp said Wisconsin's weakened manufacturing sector offered an electorate friendly to Clinton's emphasis on the urgent economic needs of blue-collar workers.
Last night, Clinton continued her criticism of Obama as an agent of rhetoric alone, a recurring motif of a Wisconsin campaign - where she touted her campaign of "solutions" versus his of "speeches" - in which she tried to establish herself as the more substantive candidate on healthcare, foreclosures, and other economic issues.
"We believe better-educated voters will choose a candidate based not on their style, but on their policy," said Stephanie Bloomingdale, director of public policy for the Wisconsin Federation of Nurses and Health Professionals, a union supporting Clinton.
But exit polls suggested that two-thirds of voters believed that Obama would be a stronger candidate in the fall and that he was more likely to unite the country.
Obama's rise bucked a move among Wisconsin Democrats toward more "centrist, cautious" politics, according to John Norquist, a former mayor of Milwaukee who endorsed Obama last week.
Yesterday's primary also offered the first test of Obama's ability to turn out votes after receiving last week the endorsement of the Service Employees International Union, a fast-growing organization with 1.9 million members nationwide The union's backing could help Obama in the upcoming Ohio and Pennsylvania primaries to offset the power of public employees' unions backing Clinton.
Obama's near-even split among union households, according to exit polls, indicated that he may have succeeded in separating the votes of rank-and-file members from their leadership even among those unions that backed Clinton or remained neutral.
Issues of concern to organized labor dominated the debate in Wisconsin. Obama tried to hold Clinton responsible for the North American Free Trade Agreement signed by her husband's administration. Clinton criticized trade policy, declaring Monday that she was "tired of being played for a patsy" on trade deals - yet neither candidate fully embraced a position against free trade.
Half of Democratic voters named the economy as their primary concern, according to exit polls conducted for the TV networks and other media organizations, and 7 out of 10 believed globalization had hurt the state. According to those polls, 1 in 7 people who voted yesterday was doing so in a primary for the first time, many under wide-open election laws that allow voters to register without party affiliation and to choose a candidate in either party off a single ballot. Voters who described themselves as independent cast about one-fourth of the ballots and overwhelmingly chose to participate on the Democratic side.
Among Republicans, yesterday's Wisconsin's primary was the first since former governor Mitt Romney of Massachusetts endorsed McCain last week, the latest step in the presumptive nominee's effort to consolidate support within the party.
"We'll see the vast majority of the Romney vote go to McCain," said Terry Dittrich, a Wisconsin businessman who served on Romney's national finance committee before he dropped out of the race nearly two weeks ago. "There's some bridge-building to be done, but this party tends to rally around."
Huckabee, who has pledged to compete until a candidate can claim the 1,191 delegates needed for the nomination, said last night in Little Rock that "we're going to keep marching on."
Based on partial returns from last night, McCain had at least 939 delegates to Huckabee's 245. McCain was also the projected winner last night in the primary in Washington state, where an additional 19 delegates were at stake.
The two winners in Wisconsin quickly set their sights on one another. McCain accused Obama of promising "no more than a holiday from history and a return to the false promises and failed policies of a tired philosophy that trusts in government more than people." Obama responded in Houston, saying McCain "represents the policies of yesterday."
"The problem that we face in America is not the lack of good ideas," Obama added. "The problem is we haven't had leaders who could rally people behind a common purpose."
Sasha Issenberg can be reached at sissenberg@globe.com.
