WASHINGTON (AP): Hillary Rodham Clinton went on the offensive ahead of key primaries in the Democratic presidential race, accusing Barack Obama of misrepresenting her views in mailings to voters. She also reached out to black voters, who have overwhelmingly supported her opponent.

Obama has won 11 straight primaries and caucuses to lead in the race for the Democratic nomination. Some of Clinton's supporters have said she must win both Ohio and Texas on March 4 to keep her White House bid alive. Recent polls show Ohio is close, and Texas closer.

Clinton on Saturday accused Obama of deliberately misrepresenting her positions on health care and trade in mass mailings to voters. ``Shame on you, Barack Obama,'' she said at a Saturday rally in Cincinnati.

Clutching two of the mailings in her hand for emphasis at a rally in Cincinnati, Ohio, the former first lady said, ``Enough with the speeches and the big rallies and then using tactics that are right out of Karl Rove's playbook.'' She was referring to the former top adviser to President George W. Bush.

Obama defended the mailings as accurate and rejected Clinton's complaint as a political ploy. He said that despite her current criticism of the North American Free Trade Agreement with Canada and Mexico, Clinton supported the trade agreement when it passed during her husband's administration.

``You can't be for something and take credit for an administration ... and then when you run for president say that you didn't really mean what you said way back then. It doesn't work like that,'' he said to cheers at a rally in Akron, Ohio.

On the Republican side, John McCain inched closer to clinching the party's presidential nomination by picking up a total of 18 more delegates Saturday at Republican conventions in American Samoa and the U.S. Commonwealth of the Northern Mariana Islands.

The Democrats' long-distance clash Saturday erupted as the two campaigned separately across Ohio.

Clinton's frustration was evident as she criticized Obama in unusually strong terms _ a few days after ending a nationally televised debate by saying she was ``honored to be here with'' him in a historic race between a black man and a woman.

In her criticism of Obama, she asked, ``Since when do Democrats attack one another on universal health care?''

Obama had a ready reply to that. ``Well, when she started to say I was against universal health care ... which she does every single day,'' he said.

Since late last year, Clinton has consistently attacked Obama's health care plan, saying it would leave 15 million Americans uninsured.

Clinton's advisers have repeatedly criticized the Obama campaign's mailings, both of which went out in the last several days.

One says her plan for universal coverage would ``force'' everyone to purchase insurance even if they can't afford it. Her plan requires everyone to be covered, but it offers tax credits and other subsidies to make insurance more affordable.

Obama's plan does not include the so-called ``individual mandate'' for adults, and he has argued that people cannot be required to buy coverage if they can't afford it. He has said his first priority is bringing down costs.

The Illinois senator's plan does include a mandate requiring parents to buy health insurance to cover children.

In the overall race for the Democratic nomination, Obama leads with 1,362 delegates. Clinton has 1,266.5, getting the half-delegate from the Democrats Abroad primary. It will take 2,025 delegates to secure the Democratic nomination at the party's convention in August.

Later Saturday, Clinton reached out to black voters by speaking at the annual State of the Black Union conference hosted by Tavis Smiley of the public broadcaster PBS. Obama declined, saying he needed to campaign through Ohio and Texas.

At the event in New Orleans, Clinton pushed back hard on the notion that Bill Clinton had inflamed racial tensions while campaigning for her in the run-up to South Carolina's primary last month.

The former president _ once so popular among black voters that he was dubbed the first black president by novelist Toni Morrison _ harshly criticized Obama in South Carolina, producing a backlash among blacks that helped lead to his wife's crushing defeat there.

After that primary, the former president then angered many by suggesting Obama had won the state simply because he was a black candidate campaigning in a state with a large number of black voters. Since then, Clinton has badly lost the black vote to Obama in every primary or caucus.

Questioned by Smiley about her husband's efforts in South Carolina, the former first lady said many of the 5,000 people attending Saturday's conference were personally acquainted with the former president and that they ``know his heart.''

Speaking broadly of her husband on matters of race, Clinton said: ``My husband mended, so as to avoid ending, affirmative action. My husband had in his White House, Cabinet, and his administration, many of you I see here. We know that when he was president, we had a rising tide and we lifted more people out of poverty than at any time in America's recent history.''

But, she added, ``If anyone was offended by anything that was said _ whether it was meant or not, misinterpreted or not _ obviously I regret that.''

While the Democrats were locked in a close battle, the Republican race is considered settled in favor of McCain, the veteran Arizona senator and a former Vietnam prisoner of war.

The nine delegates each that McCain won Saturday from American Samoa and the Northern Marianas gave him a total of 976 delegates.

Former Arkansas Governor Mike Huckabee is still in the Republican race but didn't win any delegates Saturday and is far behind with 254 delegates overall. It takes 1,191 delegates to secure the Republican nomination at the party's convention in September.

On Saturday night, Huckabee made an appearance in a comedy skit on the television show ``Saturday Night Live'' that played on his reluctance to leave the race by having him miss his cue, twice, to leave the set.