The first-of-its-kind proposal would allow private citizens to sue anyone who helps a Missouri resident have an abortion — from the out-of-state physician who performs the procedure to whoever helps transport a person across state lines to a clinic, a major escalation in the national conservative push to restrict access to the procedure.

Republican state Rep. Mary Elizabeth Coleman, who is pushing the Missouri policy as an amendment to multiple health bills, said it specifically targets a Planned Parenthood clinic in Illinois just across the river from St. Louis that opened in 2019 with the explicit goal of serving Missouri patients…

Legal scholars say the Missouri proposal opens a Pandora’s box that could force courts to contend with questions that date to the Fugitive Slave Act two centuries ago.

“There’s no clear precedent saying that states can’t try to regulate out-of-state conduct if it has some effect in-state or if it [involves] one of their citizens,” said David Cohen, a professor of law at Drexel University’s Kline School of Law and co-author of a forthcoming paper in the Columbia Law Review on impending interstate conflicts in abortion law. “What these laws are doing is saying, ‘We have a different understanding of how America works, and that understanding is that if you live in this state, we control you everywhere you are.’”