Fresh from a 41-point high in West Virginia on Tuesday night, Sen. Hillary Clinton's campaign came to a crashing low less than 24 hours later when her opponent for the Democratic presidential nomination, Sen. Barack Obama, received major endorsements. John Edwards, who only last week refused to commit to either candidate, gave his support to Obama at a campaign rally held Wednesday in Grand Rapids, Michigan. Within hours of the former North Carolina senator and Democratic presidential candidate's endorsement, Obama picked up four of the 19 delegates Edwards had won before bowing out of the race in January, according to the Associated Press. One came from New Hampshire while the other three were from South Carolina. The AP reports Obama also gained the support of superdelegate Rep. James McDermott of Washington state, who currently serves as chairman of the Ways and Means Subcommittee on Income Security and Family. Edwards' backing of Obama couldn't have come at a worse time for Clinton, who at the time of Edwards' announcement was just about to host major donors at her Washington, D.C. home to make a case for their continued support of her candidacy. "The reason I am here tonight is the voters have made their choice, and so have I," Edwards said. "When this nomination battle is over, and it will be over soon, brothers and sisters, we must come together as Democrats and in the fall stand up for what matters in America and make America what it needs to be." Edwards' endorsement followed another blow to the Clinton campaign when NARAL Pro-Choice America, a major reproductive rights advocacy group, switched its support to Obama. NARAL's endorsement signaled that even members of Clinton's core constituency are now reconsidering the viability of her ongoing pursuit of the nomination, political analysts point out. Another coup for Obama came Thursday when the United Steelworkers Union (USW), which had endorsed Edwards, announced it now backed Obama. UWA has 600,000 active members, and many of them are the same blue-collar workers Clinton's campaign has targeted. In a released statement, the union cited Edwards' deep commitment to working people and his belief that unfair trade policies must be changed as among views widely shared by its members. "We find ourselves once again in agreement with Sen. Edwards, this time with his decision last evening to endorse Sen. Barack Obama," the USW stated, promising to work hard for Obama. In a brief statement issued Wednesday evening, Terry McAulliffe, Clinton campaign chairman, said, "We respect John Edwards, but as the voters of West Virginia showed last night, this thing is far from over." But the numbers don't match the New York senator's optimism. Since Obama's win in the North Carolina primary last week, he has received more than 30 superdelegate endorsements, including the 4.5 he picked up on Wednesday. According to AP's delegate count, Obama has 1,892 of the 2,026 needed to win, while Clinton trails with 1,718. So, if Edwards' remaining delegates switch their allegiance to Obama, combined with endorsements and a positive outcome from the upcoming Oregon primary, Obama may cinch the nomination on May 20, as his campaign has predicted. David Bositis, a research analyst at the Joint Center of Political and Economic Studies, is optimistic the numbers will be in Obama's favor. "I think there's a good chance he'll have the number he needs thanks to Oregon and some additional superdelegates he'll pick up between now and then," he says. So, why do some delegates continue to hold back their endorsement, which in effect shortens the amount of time the Democratic Party needs to repair wounds and prepare for the general election this fall? As Hilary Shelton, director of the NAACP's Washington bureau, explains, "Delegates have a role to play beyond who will be the nominee. They're also engaged in what the platform will be and holding back to leverage their own issues and concerns as platform planks are determined." Shelton adds that as primaries took place across the country, despite their longstanding relationships with either candidate, "it became more evident that there was a need for superdelegates to readjust themselves to support the popular vote. If they didn't move in tandem with the popular vote, it would create major havoc on the appearance of fairness." Ronald Walters, a University of Maryland political scientist, agrees that there's more to these endorsements than a preference for one candidate over the other. "If you get inside the superdelegate tent and ask yourself what's their interest, sure, they have an interest in the party and winning, but they also have personal interest. Many are going to be running in the fall and they are making a bet on what's going to happen," he says. Some, such as South Carolina Rep. James E. Clyburn, who is also the House majority whip, just want to see the process play out. Each time he appears on political talk shows, hosts try to coax or cajole an endorsement out of him. Of the House leadership, whose members have not yet announced endorsements, he says, "Sure, we've got our preferences, but we still have to run the House and get legislation passed. So, we decided to stay out of any kind of partisan stuff at this point. It has nothing to do with the candidates and more with our responsibilities to the House Democratic caucus." Shelton argues that the prolonged course of action has been good for the democratic process, which has encouraged record high participation and registration of new voters. He says, "What's wonderful about this primary season is that no state is being taken for granted. Every single popular and delegate vote makes a difference. Rather than making tacit bids, or whistle stops, in various states, the candidates have had to restructure and run full-fledged campaigns in every state, and it's been very good for the democratic process."