WRAPUP 2-Obama says he will fine-tune his campaign

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By Jeff Mason

INDIANAPOLIS, April 25 (Reuters) - Democrat Barack Obama said on Friday he would fine-tune his U.S. presidential campaign and remind voters of his humble roots after a defeat in Pennsylvania fueled in part by his failure to win over working-class voters.

Obama leads the Democratic race but is in a grueling battle with Hillary Clinton for the right to face Republican John McCain in November's presidential election. Nine of the state-by-state nominating contests remain before voting ends on June 3.

Obama, an Illinois senator, said he would make adjustments after losing Pennsylvania's primary election to Clinton on Tuesday. That followed another big-state loss to Clinton, a New York senator, in Ohio in March.

"There's no doubt that a campaign has to continually fine-tune itself," Obama told reporters in Indiana, one of two crucial battlegrounds in the next round of contests on May 6.

"You know this has been a long campaign. What worked well three months ago, if you're doing the exact same thing now, it may not work as well," said Obama, who racked up a string of wins in February before stumbling in Ohio and Pennsylvania.

SPECIAL INTERESTS

Standing at a gas station, Obama said his rivals were part of a Washington political establishment that had failed to rein in oil companies and other powerful special interests.