During Tuesday night’s debate, Bill Burton, a spokesman for Senator Barack Obama, sent an e-mail message to political reporters. “Did John McCain just refer to Obama as ‘that one’?” the message said.

Indeed he had. Mr. McCain had been speaking of an energy bill that was “loaded down with goodies, billions for the oil companies, and it was sponsored by Bush and Cheney.”

“And you know who voted for it?” he asked. “You might never know. That one,” he said, smiling and pointing to Mr. Obama, without looking at him.

After the debate, Mr. Obama’s aides rushed to the spin room and pronounced the phrase “odd.” Many people posting comments on the Internet kicked up a storm, as did callers to black talk radio, saying Mr. McCain had dehumanized and disrespected a fellow senator.

Some offered a benign interpretation, saying Mr. McCain used the term frequently and had simply been clumsy this time. Others, like Warren Ballentine, an African-American host of a syndicated radio program who is a strong Obama supporter, said his chat room “exploded” with objections during the debate, and he devoted much of Wednesday’s show to the phrase.

“It was totally disrespectful,” Mr. Ballentine said in an interview. “If you disrespect someone who is your equal, how will you treat me as a citizen?”

Nicolle Wallace, a spokeswoman for Mr. McCain, said she was astounded that during an economic crisis, the Obama campaign was “again proving to be the fussiest campaign in American history.”

Mr. Burton was asked Wednesday on MSNBC to specify his objection to the phrase. He replied that in their first debate Mr. McCain did not look at Mr. Obama and that in Tuesday’s, “he didn’t say his name.”

Some apparent Obama supporters saw a merchandising opportunity, creating a Web site, www.thatone08.com, and a companion Facebook page to sell T-shirts emblazoned with the Obama campaign logo next to a new slogan: “That One 08.”