In U.S. politics, Barack Obama, a top contender for the Democratic Party's presidential nomination, is trying to gain the support of former candidate John Edwards in Obama's contest against Hillary Clinton.

Obama, a senator from Illinois, broke away from a busy round of campaign appearances Sunday for an unannounced visit to Edwards at his home in Chapel Hill, North Carolina.

Edwards has not yet endorsed either Obama or Clinton, a senator from New York and the wife of former President Bill Clinton. The former North Carolina senator was running third among Democratic presidential hopefuls before dropping out of the race last month.

Obama and Clinton are in a tight race for their party's nomination. Both candidates stopped in Wisconsin Sunday, campaigning for votes in the state's primary election on Tuesday.

Meanwhile, Republican Party frontrunner John McCain, promised in a televised interview that he will not institute any new taxes if he is elected president.

Clarifying his position on one of the controversial issues awaiting a decision on Capitol Hill, the Arizona senator said he now supports a bill to extend President Bush's tax cuts (before they expire), even though he originally voted against the tax-reduction plan. McCain has all but secured his party's nomination, but former Arkansas Governor Mike Huckabee continues to campaign for Republicans' votes in upcoming primary elections and political caucuses.

The Republican ballot in Wisconsin offers voters a choice for president of McCaion, Huckabee and Congressman Ron Paul, who has run well behind the other candidates in previous primaries.

Winter weather in Wisconsin cancelled Hillary Clinton's scheduled appearances across the state. She spoke to her supporters in Milwaukee, Wisconsin's largest city, where she spent Saturday night. Obama is expected to win Tuesday's primary, but Clinton hopes to reverse a recent string of losses two weeks later, when the populous states of Texas and Ohio hold their primaries (on March 4th).

Also on the Democratic ballot is former Alaska Senator Mike Gravel, who has little funding for his campaign and has won only a slim share of the vote in this year's political contests.

Some information for this report was provided by AP and Reuters.