KEY POINTS:
WISCONSIN - Barack Obama hit back at rival Hillary Clinton on Saturday as she prepared to join him in Wisconsin, which stages the next Democratic presidential battle in three days.
Obama, a first-term Illinois senator, has beaten Clinton in the last eight contests and gained the upper hand in their duel to become their party's White House nominee in November's election.
Obama has spent four days in Wisconsin since his last round of victories last Tuesday and has a slight lead in opinion polls in the state. Clinton has focused on March 4 votes in Ohio and Texas, hoping victories there will revive her hopes.
Obama launched another advertisement on Saturday responding to Clinton's recent attacks. The New York senator has criticized him as providing more talk than action, and aired two ads in Wisconsin this week attacking his refusal to debate in the state and his health care and retirement plans.
"After 18 debates, with two more coming, Hillary says Barack Obama is ducking debates? It's the same old politics," an announcer says in Obama's new ad. The two are scheduled to debate next week in Texas and the next week in Ohio.
"The question is not who has got the policies," Obama said at a rally in Eau Claire, Wisconsin. "The question is who can get them done, who can bring people together."
Obama and Clinton were to appear separately on Saturday evening at a party dinner in Milwaukee. Clinton will campaign in the state on Sunday and Monday before Tuesday's vote.
Democrats in Hawaii also vote on Tuesday but Obama, who was born in the state, is expected to win there. Wisconsin and Hawaii have a combined 94 delegates who select the nominee at the party convention in August at stake.
Despite her absence so far, Clinton campaign officials said they will be competitive in the state. The most recent poll gave Obama a 5-point edge.
"We think that she's going to hold her own," Clinton adviser Harold Ickes told reporters.
Both candidates have recently focused on the economy. Ohio and Wisconsin are swing states with large populations of blue-collar Democrats, a key part of Clinton's constituency.
Clinton also hopes to profit in Texas through her strength with Hispanics, expected to be at least one-quarter of the state's Democratic vote.
"It is time we had a president who was a fighter, a doer and a champion for the American middle class," Clinton said on Friday during an economic round-table in Cincinnati, Ohio.
"This primary election offers a very big choice to the voters of Ohio," she said. "You can choose speeches or solutions."
Texas and Ohio have become "must win" states for Clinton, who trails Obama in the race for pledged delegates awarded by the state-by-state contests to pick a Democratic nominee.
Ickes said Clinton would nearly catch Obama in the delegate race if she won those two states and the two would be roughly even when the primary process ends in June. He said she would battle all the way to the convention if necessary.
The ultimate winner could be determined by support from 796 "superdelegates" - party insiders and elected officials who are free to back any candidate.
Republican front-runner John McCain took the day off on Saturday before claiming the endorsement of former President George HW Bush, the father of the current president, at an event in Houston on Monday.
McCain is almost certain to be the Republican presidential nominee for the November general election after defeating his main rival, former Massachusetts Gov Mitt Romney, and winning his endorsement.
McCain's nearest rival is former Arkansas Gov Mike Huckabee, who badly trails the Arizona senator in the Republican delegate count.
- REUTERS