Mr. Kerry ended his quest, concluding one of the most expensive and bitterly contested races on record, with a call to the president shortly after 11 a.m. EST, according to two officials familiar with the conversation.

The victory gave Mr. Bush four more years to pursue the war on terror and a conservative, tax-cutting agenda – and probably the opportunity to name one or more justices to an aging Supreme Court.

He will also preside over expanded Republican majorities in Congress.

"Congratulations, Mr. President," Mr. Kerry said in the conversation described by sources as lasting less than five minutes. One of the sources was Republican, the other a Democrat.

The Democratic source said Mr. Bush called Mr. Kerry a worthy, tough and honorable opponent. Mr. Kerry told Mr. Bush that the country was too divided, the source said, and Bush agreed. "We really have to do something about it," Mr. Kerry said according to the Democratic official.

With Mr. Bush holding fast to a six-figure lead in make-or-break Ohio, Mr. Kerry could give up or trigger a struggle that would have stirred memories of the bitter recount in Florida that propelled Mr. Bush to the White House in 2000.