|PIC1|Democrat Barack Obama easily beat rival Hillary Clinton in Wisconsin on Tuesday, extending his U.S. presidential winning streak and putting pressure on Clinton to win next month in Ohio and Texas to salvage her campaign.

The Obama win in Wisconsin pushed his hot streak to nine straight victories in Democratic nominating contests. Democrats in Hawaii, where Obama was born and is a heavy favourite, also were voting on Tuesday.

As the results rolled in, both Democrats looked ahead to March 4 showdowns in two of the biggest states, Texas and Ohio, which have a rich lode of 334 convention delegates at stake and where Clinton desperately needs to win.

"The change we seek is still months and miles away, and we need the good people of Texas to help get us there," Obama said at a rally in Houston after noting his win in Wisconsin.

Up for grabs in Wisconsin and Hawaii were a combined 94 delegates to the August convention that selects the Democratic presidential nominee in November's election. Obama has a slight lead in pledged delegates won in state presidential contests.

Republican front-runner John McCain also won in Wisconsin, and then later in Washington state, taking another big step toward becoming his party's nominee in the presidential election.

McCain, an Arizona senator, beat his last remaining major rival, former Arkansas Gov. Mike Huckabee, to expand his huge and essentially insurmountable lead in delegates.

"Thank you Wisconsin for bringing us to the point where even a superstitious naval aviator can claim with confidence and humility that I will be our party's nominee for president," McCain, a former Navy fighter pilot and Vietnam prisoner of war, told supporters in Columbus, Ohio.

McCain took direct aim at Obama in his victory remarks, previewing a possible general election match-up. "Will we will we risk the confused leadership of an inexperienced candidate?" McCain asked.

"I will fight every moment of every day in this campaign to make sure Americans are not deceived by an eloquent but empty call for change that promises no more than a holiday from history," he said.

Obama took his own shot at McCain, noting his support for President George W. Bush's economic policies and his support for a prolonged U.S. military presence in Iraq.

"He represents the policies of yesterday and we want to the be the party of tomorrow," Obama said.

Obama's win in Wisconsin was particularly meaningful, coming in a general election swing state with a large population of blue-collar workers - a big part of Clinton's constituency and a similar demographic to Ohio.

The primary also was an open contest allowing participation by Republicans and independents, not the small, closed caucus states where Obama has performed well.

Democrats open their caucuses for presidential preference voting in Hawaii at 7 p.m. HST (5 a.m. British time on Wednesday).

Clinton, a New York senator and former first lady, is the early favourite in both Texas and Ohio, although one public opinion poll in Texas on Monday showed the race in a statistical dead heat.