Philadelphia ? In remarks both rousing and cutting, a top NAACP official Sunday evening castigated the Bush administration, saying the Republican Party “appealed to the dark underside of American culture” and relied on “the politics of racial division to win elections and gain power.”

Speaking to about 8,000 delegates gathered for the organization’s 95th annual convention, themed “The Race Is On!”, NAACP chairman Julian Bond called on the black community to launch massive voter-registration and get-out-the-vote efforts.

The largely unspoken, but apparently widely understood objective: to defeat George Bush in November’s general election.

“If you don’t vote because you fear your vote won’t count, you’re absolutely right — if you don’t vote, you won’t count,” said Bond, whose speech, on the second day of the six-day gathering, officially opened the convention. “You’ll be letting the bad guys win. Our response must be determination — to flood the polls and cast our votes in such large numbers that there will be no doubt.”

To rousing cheers and frenetic applause, Bond lambasted the GOP for what he said was an unraveling of social programs and civil-rights gains, for waging a war overseas while ignoring the problems at home.

His criticism was not just reserved for the GOP. While clearly pushing a Democratic victory, Bond took a jab at Democratic performance over the last four years, too.

“Too often they’re not an opposition; they’re an amen corner,” he said. “When one party is shameless, the other party cannot afford to be spineless.”

Bond praised U.S. Sen. John Kerry of Massachusetts, the presumptive Democratic nominee, for his spine in accepting the organization’s invitation to Philadelphia to address the convention Thursday. Bush’s decision to decline, meanwhile, prompted even more criticism.

Bush, who has declined to speak at the convention for four consecutive years and is the first sitting president in more than 70 years to do so, initially cited a scheduling conflict for not appearing this year. But on a campaign visit to Pennsylvania on Friday, he told reporters that hostility by NAACP leaders, including Bond, was keeping him away.

Administration officials added that the president had done a lot for the black community, including using black churches to deliver programs under his faith-based initiative.