CHICAGO (Reuters) - False rumors that Barack Obama was secretly a Muslim or had ties to Islamic extremism angered Muslim-Americans, who overwhelming supported him in Tuesday’s presidential election, experts said on Thursday.

President-elect Senator Barack Obama speaks to supporters during his election night rally after being declared the winner of the 2008 U.S. Presidential Campaign in Chicago, November 4, 2008. REUTERS/Jim Bourg

Unpublished polling data indicated that the Democratic President-elect got somewhere between 67 percent and 90 percent of the Muslim vote, probably nearer the higher end, Ahmed Younis of Gallup Center for Muslim Studies, said in a telephone briefing.

A “watershed” moment for U.S. Muslims occurred in mid-October, he said, when former Secretary of State Colin Powell, a Republican who endorsed Obama, addressed the Obama-is-a-Muslim rumors which had circulated for months, and condemned the idea that this would be a slur.

“Is there something wrong with being a Muslim in this country?” Powell asked on NBC’s “Meet the Press.” “The answer’s no, that’s not America ... Yet I have heard senior members of my own party drop the suggestion ‘he’s a Muslim and he might be associated with terrorists.’”

Younis said that for U.S. Muslims Powell’s comment capped a decades-long search “to become part and parcel of the nation.”

Muslims make up less than 1 percent of the U.S. population of 305 million, according to the Pew Forum on Religion and Public Life, though some believe that number is low.

Obama, whose father was Kenyan and whose mother was a white woman from Kansas, has the middle name Hussein, and lived for part of his childhood in predominantly Muslim Indonesia. He is a Christian.

Jen’nan Read, professor of sociology at Duke University, told the same briefing that not only did the whisper campaign about Obama being a closet Muslim fail, but that distribution in closely contested states of a video on Islamic extremism backfired.

VIDEO BACKFIRED

More than 20 million copies of a film called “Obsession: Radical Islam’s War Against the West” were included as advertising supplements in newspapers, distributed by a private group unaffiliated with Republican John McCain’s campaign. The film features suicide bombers, children being trained with guns, and a Christian church said to have been defiled by Muslims.

Read said the video was a subtle attempt to link Obama to Islamic extremists but many of the states where it was handed out “were strongholds of Muslim American voters” who were prompted to work for Obama.

“It may actually have brought out voters for Obama,” she said.

But beyond that issue, she added, Muslim voters looked a lot like many other American voters. They moved away from the Republican party, which they had backed heavily in 2000 but less so in 2004 -- and voted their concerns for issues such as the economy and a desire for a change in leadership.

Mukit Hossain, executive director of the Muslim American Political Action Committee, said at the briefing that support for Obama among Muslims “changed dramatically” in the last three to four weeks of the campaign “when people started calling Obama a terrorist” in the crowds at Republican rallies.

He also said a concern for erosion of civil liberties since the attacks on the United States of September 11, 2001, has driven Muslims away from the Republican party in recent years.

Although hard numbers are difficult to find, Hossain said from 2 million to 3 million Muslims were probably registered to vote in this year’s election.