Democratic primary voters in Texas an Ohio this week play an important role in the close presidential nomination contest between Sens. Hillary Clinton of New York and Barack Obama of Illinois. Hundreds of delegates to their party's convention in Denver this August will be allocated according to each candidate's share of votes Tuesday, when primaries also take place in Vermont and Rhode Island. In all, 370 delegates are at stake.

Because the race could remain ultra-tight, its outcome may pivot on the preferences of 796 "superdelegates" – a label given to party leaders, top elected officials and other automatic delegates guaranteed a convention seat and nominating vote. Unlike delegates chosen as a result of primaries or causes, who are pledged to specific candidates, superdelegates are free agents who decide on their own whether to back Obama or Clinton. Most are Congress members or party bigwigs in the Democratic National Committee.
Former First Lady Clinton leads the first-term Illinois senator by a margin of roughly 240-180 among superdelegates, by the latest Associated Press count. The cable network MSNBC sees a slightly closer split of 256-200 in Clinton’s favor. That leaves about 340 to 370 who haven't decided or won't say.

This sets the stage for a dramatic finale at the convention if Clinton and Obama remain in the race to run against Republican John McCain and neither reaches the magic number of 2,025 Democratic delegates. If Clinton does well this week and in the two largest primaries remaining – Pennsylvania’s on April 22 and North Carolina’s on May 6 – fasten your seat belts for a bumpy ride.

Superdelegate says: "If 795 of my colleagues decide this election, I will quit the Democratic Party. I feel very strongly about this." -- Donna Brazile, member of the Democratic Naional Committee

Democratic strategist says: "The perception that the votes of ordinary people don’t count as much as those of the political insiders, who get to pick the nominee in some mythical back room, could hurt our party for decades." – Tad Devine, past campaign aide to former Vice Presidents Al Gore and Walter Mondale

Protest group says: "The Democratic Party must be democratic. The superdelegates should let the voters decide between Clinton and Obama, then support the people's choice." -- Online petition at MoveOn.org