A vacancy on the general election ballot exists when any political party lacks a candidate for an office to be filled at the general election because:
Iowa Code § 43.77
89 Acts, ch 136, §21; 94 Acts, ch 1180, §7, 8; 2009 Acts, ch 57, §8; 2017 Acts, ch 110, §68; 2020 Acts, ch 1062, §16; 2020 Acts, ch 1063, § 22