Senator Obama of Illinois is apologizing personally for an opposition research document in which his presidential campaign mocked Senator Clinton over her ties to India and the Indian-American community.

“The memo’s caustic tone and its focus on contributions by Indian-Americans to the Clinton campaign was personally hurtful, and as such, unacceptable,” Mr. Obama said in a written statement. “Our campaign made a mistake. Although I was not aware of the contents of the memo prior to its distribution, I consider the entire campaign — and in particular, myself — responsible for the mistake.”

Meeting with reporters and editors at the Des Moines Register yesterday, Mr. Obama called the document “stupid.” He said it failed to take account of his views of “the complicated issue of outsourcing” and ignored his support from Indian Americans.

The document released by Mr. Obama’s campaign on a not-for-attribution basis last week referred to the former first lady as “Hillary Clinton (D-Punjab).” The accompanying summary of quotes and news stories suggested that campaign donations to Mrs. Clinton from Indian Americans and business deals involving President Clinton had led her to be sanguine about outsourcing of American jobs to India.

Mr. Obama’s campaign declined to apologize for the document shortly after it was issued and obtained by Mrs. Clinton’s campaign. The next day, Mr. Obama’s campaign manager expressed regret over the memo’s tone, but not its substance.

Indian Americans, including some in Mr. Obama’s camp, decried those responses as insufficient and demanded a more abject statement from the candidate himself.