Barack Obama has taken the lead in superdelegate endorsements for the first time, marking a potential turning point in the endgame of the Democratic primary.

Obama picked up five superdelegates Saturday, after rounding up nine such endorsements the day before. The gains erased Hillary Clinton's once-imposing lead among the party officials and insiders who play a key part in selecting the nominee.

"I think it is an encouraging sign that our camp is making progress that superdelegates are moving in our direction," Obama said Saturday in Bend, Ore. "They are looking forward to resolving this contest as soon as we can so we can pivot and start talking about John McCain and the general election."

Clinton added one superdelegate in Massachusetts, but lost two in the Virgin Islands, putting the count as of Saturday afternoon at 276 for Obama, 271.5 for Clinton.

The milestone is important because these are the Democrats who will decide the nomination for president, and Clinton would need their support by a wide margin to win. Obama has a big lead among pledged delegates, but neither candidate can win the nomination without support from the superdelegates.

Superdelegates, who make up 20 percent of the total available delegates, are free to support whomever they choose, while pledged delegates are awarded based on the outcome of primaries and caucuses.

Even as Obama steadily racked up pledged delegates over the past four months, Clinton had always led with superdelegates, a sign that she was the establishment favorite.

Obama, though, moved ever closer to clinching the nomination with his double-digit win in North Carolina on Tuesday and his better-than-expected finish in Indiana. His performance prompted a round of pundits and elected officials to declare the race was over and started the stream of superdelegate endorsements.

Training his sights on presumptive GOP nominee McCain, Obama even said Saturday he would be happy to meet the Arizona senator for joint town hall meetings, after spending weeks refusing to debate Clinton.

"That's a great idea," he said. "Obviously we would have to think through the logistics on that. But to the extent that I, should I be the nominee, if I have the opportunity to debate substantive issues before the voters with John McCain that's something that I am going to welcome. "

Obama surpassed Clinton's lead Saturday by adding superdelegates from Utah, Ohio, Arizona and the Virgin Islands.

Virgin Island superdelegates Carole Burke and Kevin Rodriquez were just two of the latest to break for Obama.

"While I have great respect for Senator Clinton ... Senator Obama has brought a new generation and energy into the democratic process and the Democratic Party," Rodriquez said in a statement.

Clinton started the year with a 106-delegate lead among superdelegates, a margin that started to shrink after Obama won the Iowa caucuses in early January.

A little more than 200 superdelegates remain undecided, and about 40 others will be named by state parties at state conventions and meetings throughout the spring.

There are 217 pledged delegates at stake in the remaining six primaries. Obama is on track to secure a majority of the pledged delegates on May 20, when Kentucky and Oregon vote.

In the overall race for the nomination, Obama has 1,864.5 delegates and Clinton has 1,697, according to the latest Associated Press tally. Obama is just 161.5 delegates shy of the 2,025 needed to secure the Democratic nomination.

Undeterred, Clinton held a fundraiser Saturday in New York that was expected to pull in $200,000.

"So let's keep going. Stay with me," she said. "This is a great adventure and we're going to make history."

FOX News' Shushannah Walshe and The Associated Press contributed to this report.