NEW PORT RICHEY, Fla. – “John McCain! Not Hussein!”

So goes the latest popular chant on the campaign trail with Gov. Sarah Palin, demonstrated at a morning rally in central Florida.

Ms. Palin was midway through her stump speech when a group of supporters began shouting it in unison, drowned out a few seconds later as Ms. Palin talked over them.

A similar chant, “Vote McCain, not Hussein,” was heard at a campaign event for Ms. Palin in Williamsport, Pa., earlier this week.

Senator Barack Obama’s middle name is Hussein, a fact that some of his opponents say proves that he is a Muslim. Mr. Obama is, in fact, a Christian.

After the rally in Florida ended, two of the people leading the chant explained why they did so.

“Because it rhymes,” said Shirley Mitten, 64, a volunteer at a pregnancy center and a resident of Brooksville, Fla.

She said she does not know if Mr. Obama is a Muslim. “He says he’s not, but we have no way of knowing,” Ms. Mitten said.

Her husband, John A. Mitten, 64, took credit for starting the chant. “I was trying to get it going!” he said. “I just do not want Obama to be elected.”

Mr. Mitten said he could not trust Mr. Obama because of his past association with William Ayers, the 1960’s radical, and because of his relationship with the Rev. Jeremiah A. Wright Jr. He also pointed out that Mr. Obama’s father was a Muslim.

The middle name Hussein, he said, added to the suspicion. “I guess Obama was named after Saddam Hussein,” he said.