Oregon anti-tax activist Bill Sizemore is suing two teacher unions and other opponents, saying they made false statements about him during the 2008 election, including calling him a racketeer.

A Marion County judge on Tuesday heard arguments in the lawsuit filed by Sizemore, who is one of the most prolific writers of ballot measures in the West.

The lawsuit says teacher union campaign mailings labeled Sizemore as a convicted racketeer, implying a criminal conviction. Sizemore says that's a false way of describing a 2002 jury award in a racketeering lawsuit against his former political action committee.

Union lawyers argued that the campaign materials are protected speech, and the jury in 2002 decided Sizemore was at the center of an alleged racketeering enterprise using forged signatures to qualify measures for the ballot.