U.S. Republican presidential candidate Mitt Romney is telling African American voters that his policies and leadership will help minority families more than President Barack Obama's have.

Romney made his appeal Wednesday in a speech to the National Association for the Advancement of Colored People , at its annual convention in Houston, Texas.

Romney told the nation's oldest civil rights group that he is running for president because he knows his policies and vision will help hundreds of millions of middle class Americans of all races, will lift people from poverty and will help prevent people from becoming poor in the first place. He called Democrats' claims that he and other Republicans are running for office to help the rich “nonsense.”

The speech was aimed at drawing voting support from African Americans, who, in polls, overwhelmingly favor President Obama, the nation's first black president.

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.

Vice President Joe Biden will address the convention on Thursday.