Democratic presidential contenders Barack Obama and Hillary Clinton are headed for a showdown March 4 in primaries in Texas and Ohio. Those primaries could go a long way toward deciding who will be the Democratic Party's nominee for president. But as VOA National correspondent Jim Malone reports from Washington, some Democrats believe that so-called superdelegates could eventually play a major role in deciding who wins the party's nomination.

If the tight Democratic presidential race continues over the next two months, it is possible that neither Barack Obama nor Hillary Clinton will secure the nomination before the party convention.

Under Democratic Party rules it takes 2,025 delegates to clinch the nomination. At the moment, Obama has a modest lead over Clinton, but it is possible that by the end of the primary season in June, neither candidate will have won enough delegates to claim the nomination outright.

Eighty percent of the delegates in the Democratic Party are chosen through the primary and caucus process in which candidates are allocated delegates based on their performance in the popular vote in a given contest.

But about 800 delegates, or 20 percent of the total, are so-called superdelegates. Superdelegates are Democrats elected to public office like governors, senators or member of Congress, as well as senior party activists.

"Those are positions held open for party leaders and elected officials of that party," said Stephen Wayne, a professor of government at Georgetown University in Washington. "Unlike the regular delegates who are elected by the people and pledged to support a certain candidate, the superdelegates are unpledged."

Although some superdelegates have already committed to either Clinton or Obama, most remain uncommitted and have become the subject of intense political pressure from both campaigns.

Senator Ben Cardin of Maryland is an uncommitted superdelegate. Cardin told MSNBC television that he has yet to decide which candidate he will support for the Democratic nomination.

"It is very exciting, two great candidates," he said. "I think either one would be a great president. I get interest from the different candidates. I also get interest from people in Maryland as to whom I support. And I tell them, look, we have a great choice, two good people running, and I am going to be very comfortable whoever our nominee is."

Democrats established the idea of superdelegates in the early 1980s, following the landslide loss by President Jimmy Carter to Republican Ronald Reagan in the 1980 election.

Party leaders wanted to bring longtime activists and elected officials back into the nominating process after they were marginalized by reforms in the 1970s that stripped the nominating power from party bosses.

Tad Devine, a longtime Democratic strategist not affiliated with either the Clinton or Obama campaigns, says a special Democratic Party commission formally proposed the idea of superdelegates in the early 1980s.

"That commission introduced the concept of superdelegates, so that we would have elected officials more broadly represented at the convention," he said. "Not many of them came to the 1980 convention. They did not want to have to pick between an incumbent president and a popular figure within their party, so a lot of them stayed away. Party leaders realized that this was hurting the chances of a nominee."

Superdelegates were created so that senior party members and veteran Democratic office-holders would have a role in the nominating process and act for the good of the party as a whole, and not necessarily for a specific candidate.

Given the tight race between Clinton and Obama, political analyst Stuart Rothenberg says they may have a role to play in swinging the nomination one way or the other, either before or during this year's Democratic nominating convention in Colorado in late August.

"Superdelegates could play the role," said Rothenberg. "Now superdelegates have preferences, but they also have another role, and that would be to pick the strongest nominee and to make sure things run smoothly."

Superdelegates can wait until the Democratic national convention in late August before committing to a candidate. But many experts believe most of them will make their choice long before that to avoid the possibility of a divisive party convention.

Some Democrats are already warning against the idea of the superdelegates playing a decisive role in the nomination fight, especially if they pick the candidate who is trailing in the delegate count or popular vote from the various primaries and caucuses.

Democrat Douglas Wilder, the mayor of Richmond, Virginia, and the first African-American to have served as governor of that state, supports Barack Obama for president and told the CBS television program Face the Nation that the superdelegates should remain on the sidelines for now.

"If the superdelegates intervene and get in the way of it and say, oh no, we are going to determine what is best, there will be chaos at the convention," he said. "It does nothing to help the Democrats."

Barack Obama has won 10 straight nominating contests in his battle with Hillary Clinton, and many experts predict that Democratic Party leaders will be reluctant to hand the nomination to a candidate trailing in both the delegate count and the popular vote.

"I cannot imagine that the Democrats, psychologically, could overturn the popular vote," said Larry Sabato, who directs the Center for Politics at the University of Virginia. "So, that is a big plus for Obama."

Democratic superdelegates did make a difference in the 1984 nomination battle between former vice president Walter Mondale and then senator Gary Hart. The superdelegates swung their support to Mondale at the national convention and helped to defeat Hart, even though Hart had beaten Mondale in several state primaries and caucuses earlier in the year.