The Angus Reid Public Opinion poll found 58 percent of the 1,005 people it surveyed April 6-7 think a terrorist attack on U.S. soil, carried out by Americans, is "very likely" or "moderately likely" to happen in the next year.
Even more Americans, 69 percent, think it is very likely foreigners will attack in the United States within 12 months, the poll indicates.
The poll also found 51 percent consider the anti-government groups Hutaree and Guardians of the Free Republics to be "terrorists" and 8 percent think of them as "freedom fighters." Hutaree members have been arrested in Michigan for allegedly plotting to kill law enforcement officers and the Guardian group recently sent letters to state governors across the country demanding they resign within three days or be removed.
The survey's margin of error is 3.1 percentage points.