Democrats clashed Sunday over the pivotal role of unelected party leaders whose votes could determine whether Hillary Clinton or Barak Obama win the party's presidential nomination in August.
The feud over how to select the Democrats' candidate for the 2008 election came as both candidates faced freezing weather to woo working class votes in the Midwestern state of Wisconsin, which holds a primary on Tuesday.
Clinton is struggling to halt gathering momentum for her rival Obama, who has won eight straight contests and holds an edge in campaign funds.
Trailing Obama in the popular vote so far, the Clintom campaign argued that hundreds of "superdelegates" -- party activists and elected officials who get a vote at the Democratic convention in August -- were not bound by the results of voting in their home states.
Governor Ted Strickland of Ohio, a supporter of the former first lady and himself a superdelegate, told Fox television the independence of superdelegates was part of the process, and "those are the rules."
As a superdelegate, Strickland said "I think my responsibility is to vote my conscience, and I intend to do that."
But Wisconsin Governor Jim Doyle, a pro-Obama superdelegate whose state votes Tuesday, said that approach would defy the popular will and damage the party.
"I think it would be an absolute disaster for the Democratic Party for the superdelegates to undo the will of the people who have been selected in the primaries and in the caucuses and by the rules that were set out," he told Fox.
In a close race governed by elaborate party rules, neither candidate may emerge from the state-by-state primaries with enough regular delegates to clinch the Democratic Party nomination.
Hundreds of superdelegates would then hand one candidate the party's mantle, and as of now, Clinton leads among those party leaders and lawmakers.
New York Senator Chuck Schumer, a Clinton ally, told NBC television "we are on the edge of victory here... The goal is that at the end of the day we don't have such an internecine battle that we lose the general election."
But while downplaying superdelegates' power, the Obama campaign was courting them as aggressively as Clinton.
Uncommitted superdelegates reported several contacts from both sides and promises of private meetings with Obama, Clinton and even former president Bill Clinton.
Bad weather on Sunday forced both candidates to cancel some events in Wisconsin, home to a mostly working class electorate that has shaped the outcome of previous Democratic nomination fights.
Obama meanwhile visited North Carolina out of the view of reporters to meet with John Edwards, a former rival in the White House race who has not endorsed him or Clinton, US media reported.
The candidates traded attacks in television ads and speeches, with Clinton painting Obama as inexperienced and lacking substance while he portrayed the New York senator as hamstrung by Washington's partisan ways.
Two polls gave Obama a four-point lead in Wisconsin, which has 74 regular delegates at stake. Hawaii, with 20 delegates in play, also holds caucuses Tuesday with Obama -- who was born and raised there -- favoured to win.
Clinton is pinning her hopes on delegate-rich Ohio and Texas on March 4 to stop Obama's surge and turn the race in her favour.
Including pledged superdelegates, Obama has 1,302 delegates so far, compared to 1,235 for Clinton, according to independent website RealClearPolitics. A total of 2,025 are needed for the nomination.
In the Republican race, front-runner John McCain is forecast to prevail against former Arkansas governor Mike Huckabee in Wisconsin and take another step to the 1,191 delegates he needs to secure the party's presidential nomination.
The Arizona senator already has 825 delegates in hand and has started to position himself for the November general election, charging that the Democrats would raise taxes if they capture to the White House.
Discussing the troubled US economy, McCain promised no new taxes in an interview on ABC's "This Week."
"In fact, I could see an argument if our economy continues to deteriorate, for lower interest rates, lower tax rates and certainly decreasing corporate tax rates, which are the second-highest in the world," McCain said. (AFP)
Obama, Clinton argue over 'superdelegate' power