In the U.S. presidential race, Barack Obama has now won 10 straight contests in his battle with Hillary Clinton for the Democratic Party's presidential nomination.  Meanwhile, John McCain moved another step closer to clinching the Republican nomination with two victories on Tuesday.  VOA National correspondent Jim Malone reports from Washington.

Senator Obama's momentum in the Democratic race seems to be growing after convincing victories in Wisconsin and Hawaii.

Obama has now defeated Senator Clinton in 10 straight nominating contests over the past two weeks, setting up what could be a decisive showdown in Texas and Ohio on March 4.

Obama continues to emphasize his role as an agent of change as he campaigns in Texas.

"The problem that we face in America today is not the lack of ideas.  It is that Washington has become a place where good ideas go to die," he said.

Obama has widened his lead in the delegate count and has established himself as the frontrunner for the Democratic Party nomination.

Hillary Clinton now faces the daunting prospect of trying to stop Obama's momentum in Texas and Ohio in two weeks.

Campaigning in Ohio, Clinton cast herself as more experienced than Obama and ready to assume the presidency on day one.

"One of us is ready to be commander in chief in a dangerous world.  We cannot just have speeches," she said.  "We have got to have solutions."

Some warning signs for Clinton emerged in the Wisconsin vote.  Obama overwhelmingly won men voters and nearly drew even with Clinton in the support of women voters, usually her strength.

Obama also did better among working class voters and continued to draw strong support from independent voters.  Independents are allowed to vote in both the Texas and Ohio primaries.

Anthony Salvanto manages voter surveys for CBS News.

"In Wisconsin, the economy was foremost on voters' minds, and Obama won with those who picked it as the number one issue," he said.  "The economy has been at the top of voters' minds in many primaries this season, and could be again in Ohio.  That could be where the battle is won and lost."

In the Republican race, Senator John McCain of Arizona moved closer to clinching his party's nomination with victories in Wisconsin and Washington state.

McCain is already turning his sights on Senator Obama as his likely Democratic opponent in the general election.

"I am not the youngest candidate, but I am the most experienced," he said.  "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."

But McCain first has to dispatch former Arkansas governor Mike Huckabee, who remains in the race despite a string of disappointing finishes in the recent primaries and caucuses.

Huckabee is vowing to fight on.

"To Texas we go, and Texas is a state where independence matters a lot," he explained.  "People there do not like to be told what to do, how to think or how to vote."

McCain did better among conservative voters in Wisconsin, suggesting he may be making inroads in quelling discontent on the right about his candidacy.

McCain is well on his way to securing the 1,191 delegates needed to win the Republican nomination and might be in a position to do that in the March 4 primaries in Texas and Ohio.