The due process issue was tangential. From the ruling[1]: The court did not address the Clause’s application to civil in rem forfeitures, nor did the State as

The due process issue was tangential. From the ruling[1]: The court did not address the Clause’s application to civil in rem forfeitures, nor did the State ask it to do so. Timbs thus sought this Court’s review only of the question whether the Excessive Fines Clause is incorporated by the Fourteenth Amendment. [1] https://www.supremecourt.gov/opinions/18pdf/17-1091_5536.pdf https://www.supremecourt.gov/opinions/18pdf/17-1091_5536.pdf