THE road just got rockier for Democrat Hillary Clinton in her battle to win her party's presidential nomination. The New York senator and former first lady barely survived a strong challenge from rival Barack Obama in Indiana and was routed by him in North Carolina. Obama inched ever closer to clinching the right to face Republican John McCain in the November election. “I take her at her word that she's going to go forward,” said Democratic strategist Jim Duffy. “But the math simply doesn't change. Two plus two still equals four in this race. “You can't change the numbers. The question becomes at what point is she willing to decide to concede,” he added. Hillary's defeat in North Carolina was particularly biting because she has done some of her best campaigning in the last few weeks and because her politically astute husband, former president Bill Clinton, had swept small towns across the state trying to drum up support for his wife. Clinton portrayed her slender win in Indiana as a come-from-behind victory although polls had shown her leading ahead of the vote. Before all the votes were counted, she vowed “full speed on to the White House.” But she made some conciliatory noises. “I can assure you as I have said on many occasions, that no matter what happens, I will work for the nominee of the Democratic Party ... and I know that Senator Obama feels the same way,” she said. Obama's North Carolina victory and strong showing in Indiana was a sign he had survived the furor over racially charged rhetoric from his former pastor, the Rev. Jeremiah Wright, although race still simmers in the contest. Voters surveyed in exit polls reported that the Wright issue was a major factor for them. White working-class voters went heavily for Clinton, while Obama won overwhelming black support. The 60-year-old Clinton is left with an uphill task. She must win the lion's share of nominating delegates from the remaining contests - West Virginia on May 13, Kentucky and Oregon on May 20, Puerto Rico on June 1, and Montana and South Dakota on June 3. At the same time, she must convince enough of the Democrats' “superdelegates,” those party officials who can vote for whomever they want, that she is a more electable Democrat and they should side with her. That effort was already well under way. Top Clinton adviser Harold Ickes was quoted as telling Time Magazine's The Page on Tuesday that questions still remained about Obama. “We don't know enough about Senator Obama yet. We don't need an ‘October surprise.' And (the chance of) an ‘October surprise' with Hillary is remote,” he said. Plus, Clinton must convince the Democrats to seat delegates from Florida and Michigan, whose votes she won earlier in the race but have not been recognized because the voting contests were held before national Democratic Party rules allowed. “I think it's most likely that Obama wins,” said Merle Black, a political science professor at Emory University in Atlanta. “I can't see a way that she wins the nomination without really tearing up the party.” Democratic strategist Liz Chadderdon said the close contest needs to end long before the Democrats' nominating convention in Denver in August because a convention battle would be damaging and could help the Republicans. “The truth is that the way this ends is going to determine how we end in November,” she said. “And the loser must lose gracefully. We must come together.” – Reuters __