WASHINGTON (AP) — Vice President Joe Biden is offering a rebuttal of Republican presidential candidate Mitt Romney before the nation's largest civil rights organization, defending President Barack Obama's record before black voters.

Biden is addressing the NAACP convention in Houston on Thursday, a day after Romney said he'd do more for African-Americans than Obama, the nation's first black president. Romney was booed when he said he'd repeal Obama's sweeping health care reform law but otherwise got a polite reception as he reached out to a traditionally Democratic voting bloc.

Obama's campaign countered that Romney's policies would hurt working families in the black community, an argument Biden was expected to make before the NAACP delegates. Democrats said Romney had opposed the rescue of the U.S. auto industry, the health care law and the economic stimulus, which they said helped black voters.

"While Mitt Romney tried to paint a picture of a president who failed the African-American community, we know that the reality is that President Barack Obama has delivered time and time again," said Philadelphia Mayor Michael Nutter.

Obama is not speaking to the National Association for the Advancement of Colored People this year. He spoke to the organization during the 2008 campaign and in 2009, while first lady Michelle Obama spoke to the group in 2010. The president is scheduled to address the National Urban League in New Orleans on July 25.

White House press secretary Jay Carney, asked if Obama was taking black voters for granted by skipping the NAACP meeting, noted that Obama has spoken to the organization in the past and met with its president, Ben Jealous, last year.

"His commitment to the organization and the broader community is easy to see," Carney said.

Obama has no public events on his schedule Thursday.

More than 9 in 10 black voters supported Obama in 2008 and polls have shown support at comparable levels this year. But Romney could undercut Obama in states such as North Carolina, Virginia, Ohio and Florida, all of which have large black communities, if he can persuade some black voters to support him or if they stay home on Election Day.

Romney said much more must be done to improve education in the nation's cities and noted that the 14.4 percent unemployment rate among blacks is higher than the 8.2 percent national average.

"If you understood who I truly am in my heart, and if it were possible to fully communicate what I believe is in the real, enduring best interest of African-American families, you would vote for me for president," Romney said.