Iowa Code § 60.1: Court of contest.

The court for the trial of contested elections for presidential electors or for the office of senator or representative in Congress shall consist of five judges of the district court to be selected by the chief justice of the supreme court by January 30 of each odd-numbered year, three of whom shall constitute a quorum for the transaction of the business of the court. The district court judge longest serving shall be the presiding judge of the court.