Barack Obama is gaining steadily on Hillary Clinton among Democratic superdelegates, nearly erasing her last advantage in a presidential race where those party insiders could have the ultimate say.
In a danger sign for Ms Clinton, Mr Obama over the past few months has sharply cut her lead among superdelegates - nearly 800 elected officials and party leaders free to back any candidate.
"Obama has won more delegates, he's won more votes, he's raised more money, and now you see it happening with superdelegates too," said Simon Rosenberg, head of the Democratic advocacy group NDN.
Barack Obama speaking to the media
Neither Mr Obama nor Ms Clinton is likely to win enough pledged delegates in state contests to clinch the hard-fought battle for the Democratic presidential nomination, leaving superdelegates to decide the race. The Democratic nominee will face Republican John McCain in the November election.
Despite heavy courting by Ms Clinton, most of the superdelegates who made up their minds since January backed Mr Obama. Ms Clinton's superdelegate lead dwindled to about 30 from 100 in that time.
A count by MSNBC gives Ms Clinton 256 superdelegates to Mr Obama's 225. Mr Obama, an Illinois senator, has gained steam in the past month, winning more than two dozen new commitments, compared with a handful for Ms Clinton, a New York senator.
"It has been a drip, drip, drip toward Obama," said Steven Schier, a political analyst at Carleton College in Minnesota.
It has been a drip, drip, drip toward Obama - Steven Schier
"Superdelegates can see Obama's advantages growing, and it's pretty clear it's going to be very hard for Clinton to catch him," he said. "If Obama notches a few more victories, it could become a stampede."
Mr Obama has suggested that superdelegates back the candidate with the most pledged delegates - he leads by about 130 - and popular votes. He leads Clinton by about 700,000 votes, excluding contests in Florida and Michigan that were not sanctioned by the national party.
Ms Clinton has struggled to overtake Mr Obama in the Democratic contest and has rejected calls from some Obama supporters to get out of the race.
More than 300 superdelegates remain uncommitted or have yet to be named, giving the candidate who wins the bulk of them a path to the nomination.