WASHINGTON  — Bringing an abrupt end to Sen. Barack Obama’s winning streak in the primary battles for the Democratic U.S. presidential nomination, rival Sen. Hillary Clinton reinvigorated her campaign this week by taking three of four primaries on Tuesday — including key delegate-rich states Ohio and Texas, as well as Rhode Island. Obama took Vermont and later regained some lost ground in the Texas caucuses (Texas has a primary and caucuses).  Plagued by problems garnering support last summer, Arizona Senator John McCain completed an improbable comeback by sweeping Ohio, Texas, Vermont and Rhode Island, and thus clinched the Republican nomination by surpassing 1,191 pledged delegates — the majority of delegates that is required to win the nomination at the Republican National Convention.  McCain has 1,289 delegates.  A day later, President George Bush officially endorsed McCain, his former enemy.

Hours after the primaries ended, Clinton hinted that a joint ticket with the Illinois senator might be possible. In an interview on MSNBC, Clinton noted that both she and Obama had been asked if they would pick the other as their vice presidential running mate. “Obviously, it’s premature for either of us to address it,” she said.  She added: “There is a lot of … interest in that. Many Democrats are hoping for that. We have to sort through this nominating process to see … who ends up as the nominee.”

And as it became apparent that the race is going down to the wire, talk emerged of new primaries in  Michigan and Florida, where the Democratic National Committee has said it will not seat delegates selected at primaries that were scheduled early in defiance of party rules.

According to CNN, as The Arab American News went to press, Obama had 1,520 delegates — 1,321 pledged delegates and 199 so-called super delegates. Clinton had 1,424 delegates — 1,186 pledged and 238 super delegates. To win the Democratic nomination, 2,024 delegates are needed.

Based on their current delegate counts, neither candidate can win enough delegates in the remaining primaries and caucuses to secure the nomination without the help of the nearly 800 party officials and top elected officials who also have a voice in the selection. The superdelegates, including Members of Congress, former high-level Democrats and party officials, are free to vote for whomever they please at the convention, and can change their pledges and promises at any point.

Many critics fear that a clash that ends with the superdelegates choosing the candidate will likely disillusion voters who turned out at the polls only to have their voices trumped by party elites.

But some experts disagree, saying that superdelegates are beholden to political realities and are likely to act in the best interest of the party.

“A review of the history of superdelegates suggests they are likely to play a constructive role in resolving the nomination before the convention and in unifying the party for the general election campaign,” wrote two election scholars, Norman Ornstein and Thomas Mann, in an op-ed for the New York Times last month.

“They have to go through the fire of elections themselves, or, as state or local party officials, are responsible for the election of the party’s slate. No delegates are more sensitive to the potential pitfalls of the presidential candidates or their electability than the superdelegates,” they wrote.

The history, in this case, may work out for Obama. He will likely retain the pledged delegate lead, and the superdelegates have yet to overturn the will of the voters in their 24-year history.

Obama also saw a big bump in superdelegate endorsements during a string of 11 straight primary and caucus wins since the candidates effectively split the Feb. 5 Super Tuesday “national primary.”

But with less than half of the superdelegates having declared support, the coming weeks and months promise to show whether the Democratic establishment has embraced Obama or, as some allege, the recent endorsements were an instance of superdelegates jumping on the bandwagon as his campaign gained momentum.

On Wednesday, Clinton and her campaign clearly aimed their case at those so-called “superdelegates” — a strategy that could take the nomination fight all the way to the party’s August national convention in Denver.

“New questions are being raised, new challenges are being put to my opponent,” she said. “Superdelegates are supposed to take all that information on board and they are supposed to be exercising the judgment that people would have exercised if this information and challenges had been available several months ago.”

She said voters are being drawn to her argument that she would be the better commander in chief, the best steward of the economy and that she can better confront McCain in the general election.

Obama countered that on a key national security issue — the war in Iraq — “she got it wrong” by supporting Bush’s call for authority to use of force.

As for superdelegates, Obama said he expected them to rally around him.

“I don’t think it will necessarily go to the convention floor,” he told reporters aboard his plane before taking off from San Antonio for Chicago.

He also said he will challenge Clinton on her foreign policy credentials. “Was she negotiating treaties? Was she handling crises? The answer is no,” he said. “She made a series of arguments on why she should be a superior candidate. I think it’s important to examine that argument.”

Obama has faced some other troubles in recent weeks as he came under increased media scrutiny after emerging as the frontrunner. He saw several negative news cycles involving his ties to a Chicago businessman indicted on federal corruption charges and a flap over his campaign positions against the North American Free Trade Agreement.

But barring an unlikely series of lopsided victories for Clinton in the remaining 12 contests, Obama will retain a lead in pledged delegates — creating an uphill battle for the Clinton campaign.

The current delegate count does not include delegates from Florida and Michigan, who were penalized by the Democratic Party for moving up their primaries ahead of a schedule set by the Democratic National Committee. None of the Democratic candidates campaigned in either state.

Officials in both states are showing renewed interest in holding repeat presidential nominating contests so that their votes will count in the epic race.

The Michigan governor, along with top officials in Hillary Rodham Clinton’s campaign and Florida’s state party chair, are now saying they would consider holding a sort of do-over contest by June. That’s a change from their previous insistence that the primaries their states held in January should determine how the their delegates are allocated.

Clinton won both contests, but the results were meaningless. Obama’s name wasn’t even on the Michigan ballot.

Ironically, Michigan and Florida could have held crucial primaries if they had stayed with their traditional later dates. They may yet do so if they decide to hold new contests as Clinton and Obama compete to the wire.

Clinton has been insisting that the desires of more than 2 million people who cast Democratic ballots in the two states should be reflected at the convention, which would help her catch up to Obama in the race for convention delegates. Obama has said he wants to see the delegates from the two critical swing states participate, too, but not if Clinton is rewarded for victories in boycotted primaries.

Michigan Gov. Jennifer Granholm, a Clinton supporter, told the Detroit Free Press that Clinton’s victory in Ohio changes “the landscape a bit.” She said it could open the door to a caucus, if it can be privately funded and both candidates agree.

Granholm, a Democrat, and Florida Gov. Charlie Crist, a Republican, issued a joint statement Wednesday demanding that their states’ delegates be seated. “We each will call upon our respective state and national party chairs to resolve this matter and to ensure that the voters of Michigan and Florida are full participants in the formal selection of their parties’ nominees,” the statement said.

Crist told reporters at a news conference Tuesday that he does not support having another primary at taxpayer expense. He said he discussed the option with Sen. Bill Nelson, the state’s senior Democrat. “He said the only way to consider the possibility of that is to have the Democratic National Committee pay for it,” Crist said. The Florida Democratic Party said the state estimates the cost would be $25 million.

Getting funding from the national committee might be difficult when the party has a general election to wage. Last August, the DNC offered to spend $800,000 for a later caucus, but the Florida state party rejected the idea because the amount would have only been enough to set up 150 caucus sites for the state’s 4.1 million Democrats. “It wasn’t a real offer. It just wasn’t. It was not something anybody could agree to with a straight face,” said state party spokesman Mark Bubriski.

DNC Chairman Howard Dean issued a statement Wednesday that seemed to leave the matter for the states to resolve.

Dean said Michigan and Florida have two options: either submit a new plan for a process for choosing their convention delegates, or appeal to the Convention Credentials Committee, which resolves issues about the seating of delegates.

“The Democratic Nominee will be determined in accordance with party rules, and out of respect for the presidential campaigns and the states that did not violate party rules, we are not going to change the rules in the middle of the game,” he said.

Michigan Democrats are discussing holding a “firehouse” contest in May or June that would be an alternative to a traditional primary or caucus and run by the state party, said a Democratic Party official who has been part of the discussions. “Firehouse” contests usually have fewer polling places and shorter voting hours than traditional state-run primary elections.

The party official, who spoke on condition of anonymity because the discussions are private, said there was general consensus that it could not be held at taxpayers’ expense and would attempt to generate participation from about 1 million state Democrats.

Obama’s campaign says whether to have a repeat contest is up to the national committee, but has signaled a willingness to participate. “We’re going to abide by their rules as they exist now and whatever happens in the future,” Obama campaign manager David Plouffe told reporters Wednesday.

“I don’t think it’s for our campaign or her campaign — we’re in a heated contest here — to have to be the facilitators here,” Plouffe said. “This is between the DNC and those state parties.”

This report was compiled by the Editor from news services including IPS, AP and Reuters.