PIERRE, S.D. (KELO) — A state law passed 17 years ago makes South Dakota one of the states where abortion could automatically become illegal if the U.S. Supreme Court returns jurisdiction to state governments.

The 2005 law resulted from two pieces of legislation. Sponsors of the main law were then-Representative Joel Dykstra, a Republican from Canton, and Senator Tom Hansen, a Republican from Huron. They were joined by long lists of House and Senate co-sponsors.

Their legislation conditionally repealed — meaning, it would take effect if the nation’s high court reversed itself on Roe v. Wade — five sections of South Dakota and conditionally added this replacement section that says:

Any person who administers to any pregnant female or who prescribes or procures for any pregnant female any medicine, drug, or substance or uses or employs any instrument or other means with intent thereby to procure an abortion, unless there is appropriate and reasonable medical judgment that performance of an abortion is necessary to preserve the life of the pregnant female, is guilty of a Class 6 felony.”

A class 6 felony is punishable by a sentence of up to two years in state prison and up to a $4,000 fine.

The Dykstra-Hansen bill also contained this paragraph about the effective date:

“This Act is effective on the date that the states are recognized by the United States Supreme Court to have the authority to regulate or prohibit abortion at all stages of pregnancy.”

The Legislature during that same session subsequently passed a second law that modified the effective date. Dykstra and Hansen also were prime sponsors of this modification, whose key section said:

“This Act is effective on the date that the states are recognized by the United States Supreme Court to have the authority to prohibit abortion at all stages of pregnancy.”

Whether South Dakota’s ‘trigger’ law takes effect could depend on the precise wording of a U.S. Supreme Court decision.

Governor Kristi Noem, a strong opponent of abortion — her older daughter is an official in the South Dakota Right to Life organization, and her chief of staff has a second title as “unborn child advocate” — said in a tweet Monday night she would “immediately” call a special session of the Legislature if the Supreme Court overturned Roe v. Wade.

South Dakota voters in 2006 rejected an anti-abortion law that the Legislature passed 185,945-148,648. Two years later voters statewide turned down another attempt to outlaw abortion 206,535-167,560.

Noem began her political career as a state legislator, winning her first election to the state House in 2006 and winning re-election in 2008.