U.S. Vice President Joe Biden praised President Barack Obama's health care law in an address to a civil rights group, a day after the gathering booed Republican presidential candidate Mitt Romney for vowing to repeal the reforms.

Biden spoke to the convention of the National Association for the Advancement of Colored People (NAACP) in Houston, Texas Thursday.

"He [President Obama] cut $100 billion from the federal debt over the next 10 years, providing access to affordable health care to 30 million Americans, eight million black Americans who would never have had insurance," he said.

The convention crowd cheered Biden as he outlined the differences between Obama and Romney on health care, education, energy and women's rights. He called Romney's domestic policy plan "a throw-back to the [19]50's."

President Obama also spoke to the crowd in a video address Thursday. He had been criticized for sending the vice president instead of attending the convention himself.

Republican candidate Romney received a cool reception Wednesday when he spoke to the NAACP.

Romney said his policies and leadership will help minority families more than President Obama's have in the last four years. Audience members booed him when he vowed to eliminate the president's health care reform plan, nicknamed "Obamacare."

Romney used his speech to highlight inequalities still facing African Americans, including a 14.4 percent unemployment rate, which is far above the 8.2 percent national average.  Biden did not mention the African American employment rate in his speech.

The vice president thanked NAACP members for their "loyalty." African Americans voted overwhelmingly for Obama, a Democrat and the nation's first black president, in the 2008 election.