A trial begins Thursday to determine whether South Dakota's smoking ban will be referred to a statewide vote.

Circuit Judge Kathleen Trandahl of Winner will first hear arguments on whether the South Dakota Constitution even permits a public vote on the new law, which would ban smoking in bars and casinos. The American Cancer Society argues that measure cannot be referred because it is needed for the immediate preservation of public health.

If Trandahl finds the measure cannot be referred, the trial will be over. Otherwise, the judge will hear evidence on the validity of a number of challenged signatures on the petitions calling for a public vote.

Secretary of State Chris Nelson has ruled that many of those signatures were invalid.