Iowa’s Constitution provides that “the supreme court shall have appellate jurisdiction only in cases in chancery, and shall constitute a court for the correction of errors at law, under such restrictions as the general assembly may, by law, prescribe…”
Citing this provision, members of the Iowa legislature want to impose a supermajority requirement on the Iowa Supreme Court for at least some of its decisions.
HF 2106 and SF 2153 provide no statute shall be held unconstitutional by a court of this state except by the concurrence of at least five 5 justices of the supreme court of Iowa. The court is made up currently of 7 justices.
There are two state courts of last resort that require supermajorities to strike down laws, but both are because of a constitutional provision, not a mere statute.
North Dakota Supreme Court (4/5): “The supreme court shall consist of five justices…A majority of the supreme court shall be necessary to constitute a quorum or to pronounce a decision, provided that the supreme court shall not declare a legislative enactment unconstitutional unless at least four of the members of the court so decide…” (Art. VI, § 2, 4)
Nebraska Supreme Court (5/7): “The Supreme Court shall consist of seven judges…No legislative act shall be held unconstitutional except by the concurrence of five judges.” (Art. V, § 2)