WASHINGTON — Senator McCain said today that he supports a proposed ballot initiative in his home state that would prohibit affirmative action policies from state and local governments. A decade ago, he called a similar effort “divisive.”

The reversal comes as Mr. McCain, a conservative senator from Arizona, seeks to tailor his policies and rhetoric to independent-minded voters who will determine the outcome of November election.

Both Mr. McCain and Democratic rival Senator Obama have accused each other —with good reason — of “flip-flopping,” a charge that carries weight with independents who seek consistency and authenticity in their political leaders.

Mr. McCain was asked specifically today whether he supported an effort to get a referendum on the ballot in Arizona that would “do away with affirmative action.”

“Yes, I do,” said Mr. McCain in an interview broadcast Sunday on ABC’s “This Week.”

The Republican senator quickly added that he had not seen the details of the proposal. “But I’ve always opposed quotas.”

Over the years, Mr. McCain has consistently voiced his opposition to hiring quotas based on race. He has supported affirmative action in limited cases. For example, he voted to maintain a program that encourages the awarding of 10% of spending on highway construction to women and minorities.

In 1998, a resolution pending in the state legislature would ask Arizona voters to eliminate most preferences based on race, gender, color or ethnic origin. Mr. McCain warned against using ballot proposals to outlaw quotas or racial preferences.

“Rather than engage in divisive ballot initiatives, we must have a dialogue and cooperation and mutual efforts together to provide for every child in America to fulfill their expectations,” Mr. McCain said.

The 1998 story by the Associated Press said Mr. McCain was speaking to a handful of Hispanic leaders at Washington. In his comments, he stopped short of directly criticizing the resolution pending at Arizona.

A spokesman for the McCain campaign said in a statement that the senator has always opposed hiring quotes based on race.

He believes that regardless of race, ethnicity or gender, the law should be equally applied,” the spokesman, Tucker Bounds, said. “He has long stood for the protection of civil rights and equal opportunity for all Americans.”

For the current effort at Arizona, supporters of the state constitutional amendment banning affirmative action programs have met the filing deadline to get the measure on the November ballot.

The Arizona Civil Rights Initiative filed 334,658 signatures with the Secretary of State’s office Thursday, surpassing the necessary number by more than 100,000. State officials are trying to verify that enough signatures are valid to get the initiative on the ballot.

The application for the referendum petition said the proposal would amend the state constitution to prohibit preferential treatment or discrimination by state government, state universities, school districts, counties, and local governments to any individual based on race, sex, ethnicity, or national origin.

Mr. Obama said he is a “strong supporter of affirmative action when properly structured so that it is not just a quota.”

He said he believes a university or college should be able to take into account race as well as economic class and hardship when making assessments about admissions.

Mr. Obama said Mr. McCain flipped on the issue of putting affirmative action bans on the ballot.

“These are not designed to solve a big problem, but they’re all too often designed to drive a wedge between people,” Mr. Obama said.

On that point, Mr. McCain’s spokesman did not directly answer whether Mr. McCain had changed his views about the wisdom of putting bans on affirmative action policies to the voters.

Mr. Bounds said that Mr. Obama himself today said that affirmative action is not a long-term solution, but has also said he’s a firm believer in affirmative action.

“So you tell me who is too inexperienced and has flipped on this issue,” Mr. Bounds said.