As presidential candidates Barack Obama and Hillary Clinton vie for support in next Sunday’s Democratic caucuses, a separate battle is being waged for Maine’s so-called “superdelegates.”

Under party rules, those with superdelegate status are not bound by the caucus results and can support whomever they choose. In a close contest, they could determine who gets nominated at the party’s national convention in September in Denver.

“With two strong, well-funded candidates who have a strong base of support, we’re likely to see a split,” said Tad Devine, a Democratic political consultant who helped write the Democratic Party’s nominating rules in the 1980s. “This is the first time [the process] will be tested.”

The 796 superdelegates account for 19 percent of the delegate total of 4,049. Obama or Clinton need at least half, or a minimum of 2,025 delegates, to secure the nomination.

Maine’s 10 allotted superdelegates include Gov. John Baldacci, Reps. Tom Allen and Michael Michaud, former Sen. George Mitchell and former Gov. Kenneth Curtis.

The lesser known are Maine Democratic Party Chairman John Knutson and Vice Chairwoman Marianne Stevens, along with Democratic National Committee members Sam Spencer and Rita Moran. As party chairman, Knutson can choose one more superdelegate before the state convention in June, said Arden Manning, the party’s executive director.

Some of the superdelegates have been getting pressure from the Clinton and Obama campaigns to line up on their sides.

“They’ve all called,” Stevens said. “They’ve been fairly persistent. I’ve received more e-mail from Obama, more phone calls from Clinton.”

Maine’s other 24 delegates will be picked in accordance with the outcome of the coming caucuses.