Republican Mitt Romney, making his most public overture to African American voters Wednesday in an address to the nation’s oldest civil rights group, said that he’s a better choice than President Barack Obama to help build their neighborhoods and lessen unemployment.

“I believe that 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, according to excerpts of his speech distributed by his campaign.

But Romney was greeted with boos from attendees at the NAACP’s annual meeting Wednesday in Houston when he pledged to repeal “Obamacare.”

The Republican presidential candidate faced a daunting task as he tried to appeal to a core Democratic constituency that is largely at odds with his policy prescriptions, suspicious of his record on diversity and civil rights, and largely committed to his general-election opponent.

The NAACP visit is the former Massachusetts governor’s attempt to move beyond the traditional Republican Party base by trying to deliver a message that the GOP is serious about attracting black voters.

Critics say the effort is pointless for his chances in November. Supporters say it is important for the future of the party.

Romney’s campaign began preliminary outreach efforts in May by hiring a senior black consultant to engage African American voters and by visiting a predominantly black charter school in Philadelphia. Campaign officials say those efforts will be expanded in the coming weeks in an effort to wrest as many votes as possible from President Obama.

“The governor is committed to competing in the black community. The odds are high, it’s challenging, but every percentage point that we chip away from President Obama counts,” said Tara Wall, who is consulting with the Romney campaign on outreach efforts. “There are shared values with this community around faith, family, free enterprise and education. He will highlight his record in terms of addressing health, wealth and disparity gaps and show clear distinctions between him and Obama.”

Wall said Romney had a record of lifting test scores of all students across the state and a record of bipartisanship as governor of Massachusetts, though she acknowledged there are policy differences on other issues, including health care and voting rights.

Critics said Romney’s record on civil rights and diversity were lacking and pointed to his tenure as governor. When he took office, he eliminated his state’s Office of Affirmative Action and proposed a filing fee for complaints of discrimination. During his race for Senate in 1994, Romney faced questions about diversity at his company Bain Capital, which did not have any black employees.

As governor, Romney was often at odds with the NAACP, though he did meet with black leaders occasionally.

“We protested against the Romney administration more than I care to remember. He had a very poor record, and he did absolutely nothing in the area of progressive legislation in civil rights and he did everything to try to dismantle the initiatives that were in place before he took office,” said Leonard Alkins, president of the Boston chapter of the NAACP from 1995 to 2006. “We had so many issues that we felt were falling on deaf ears with the administration. But in his four years in office, he never met once with the NAACP in Boston.”

This year, the theme of the conference — “This is my power. This is my decision. This is my vote” — speaks to the vast policy divide that Romney confronts in his attempts to engage African American voters.

The NAACP and other civil-rights organizations have been on the front lines in battling new laws in nearly a dozen states that require voters to have identification when they go to the polls.

Romney has come out in favor of such laws, which critics say disproportionately affect minority voters.

The conference, which has drawn some 5,000 delegates to Houston, marks an opportunity for Romney to address this issue and to reach out to African American voters more broadly as he seeks the White House.

“Clearly we want to hear from Governor Romney on voting rights and we want him to talk about why his party is leading the charge to roll back the Affordable Care Act, and we want to hear his strategy about reducing the unemployment rate in the African American community,” said Roslyn Brock, the director of the national board of the NAACP. “We want to see if he has a track record on diversity in its broadest sense, gender and race, and economic. We want to know if he can have empathy for people who are living at the bottom of the economic stratum. These are all critical issues.”

Vice President Biden, who Brock called a friend of the organization, will speak at the conference on Thursday.

Speaking at the NAACP annual convention has been a tradition for presidential candidates in an election year, yet in the age of Obama, the task has been somewhat trickier for Republicans, who have viewed the organization as partisan.

(Sen. Bob Dole skipped the convention in 1996 and said the invitation was an attempt to set him up).

In 2008, Sen. John McCain focussed on education reform and opened his remarks by praising Obama as “an impressive fellow in many ways.”

“His success should make Americans, all Americans, proud. Of course, I would prefer his success not continue quite as long as he hopes,” he said, adding that Obama’s success was a milestone. “Sen. Obama has achieved a great thing — for himself and for his country — and I thank him for it.”

In 2000, Bush acknowledged the legacy of slavery and racism, and admitted that the Republican party had not always “carried the mantle of Lincoln.”

African American voters have been a reliable Democratic constituency since 1964, when Barry Goldwater earned just 6 percent of the black vote, down from Richard Nixon’s 32 percent in 1960. And while George W. Bush’s 2004 campaign is seen as a model for Republicans seeking inroads among black voters — he managed to earn 11 percent in 2004 — his share of the black vote was actually smaller than Bob Dole’s and Ronald Reagan’s, who both earned 12 percent of the black vote .

McCain earned 4 percent of the African American vote in 2008.

The latest Washington Post/ABC News polls show Obama with a sizeable lead over Romney among blacks — 92 percent to 6 percent.

One starting point for the Romney campaign is rallying support among black Republicans, many of whom were at best ambivalent about John McCain in 2008 and saw Obama as a symbol of racial progress.

Ron Christie, a black Republican strategist, said that Obama’s record trumps his race and that Romney has an opening on the economy, given the high unemployment among African Americans — the June rate is 14.4 percent, up from 13.6 percent in May.

Yet the NAACP speech cannot just be about checking a box, Christie said.

“This just can’t be a one-stop-shop opportunity. He needs to continue his outreach and dialogue and listen to concerns that are expressed” Christie said. “He has a great opportunity to engage with a constituency and to establish a rapport of trust that he will continue in the weeks and months and years to come if he is elected president.”

So far, the campaign has spent little money on advertising on black outlets, but Wall, who helped coordinate black outreach efforts for the Republican National Committee in 2004, said it’s still early.

Former Alabama congressman Artur Davis, who recently switched his party affiliation from Democrat to Republican, said that Romney isn’t likely to change many minds but that the GOP must think about the party’s path “post-Obama, when the intense attachment that African Americans feel towards Barack Obama is not going to be a factor.

“I don’t know that Mitt Romney is going to the NAACP to get votes, and I don’t know that he is going there to persuade any sizable numbers of black voters to vote for him. I don’t see any realistic chance of Romney doing any better than John McCain, and it’s not a terribly important question,” Davis said. “The more relevant test is whether a President Mitt Romney is going to govern in an inclusive way. There is a group of white voters who don’t want to vote for a party that is racially exclusive . . . so Mitt Romney reaching out to African Americans is perhaps a statement to those group of voters.”