There are two important questions:
1. Does the 14th Amendment incorporate the Excessive Fines Clause of the 8th against the states; and
2. If so, are civil forfeiture schemes in violation of the 8th (and how in the hell not a violation of ordinary due process as well)?
Supreme Court Will Hear Case on the Excessive Fines Clause that Could End Up Curbing Asset Forfeiture Abuse
The case will decide whether the Excessive Fines Clause of the Eighth Amendment applies to the states. If so, it will also have to address how much it restricts asset forfeiture.
As to the 14th A. incorporation stuff: https://reason.com/volokh/2018/06/18/su ... -the-excesThe more difficult questions raised by Timbs are the extent to which the Excessive Fine Clause covers asset forfeiture as well as ordinary criminal fines, and what counts as "excessive."
Asset forfeiture abuse is a serious problem that often victimizes innocent people and particularly harms the poor. For these reasons, among others, it has attracted widespread opposition on both right and left. In many states, owners have little opportunity to contest forfeiture, thereby enabling authorities to hold on to their seized property for months or even years, without so much as a hearing. In recent years, many states have enacted laws curbing asset forfeiture and a few have even abolished civil forfeiture altogether. Unfortunately, Attorney General Jeff Sessions last year reinstituted a federal policy that helps state and local law enforcement agencies circumvent state limitations on forfeiture and keep a hefty share of the profits for themselves. Sessions' actions drew bipartisan opposition, but reforms that passed the House of Representatives by unanimous vote have stalled in the Senate.
Asset forfeiture technically differs from a fine because the former involves seizure of specific property that was allegedly used in the course of committing a crime, rather than imposition of punishment against a perpetrator (which, if it takes the form of a fine, can be paid using any assets the defendant owns). Nonetheless, the Supreme Court has already ruled that at least some asset forfeitures are covered by the Clause in the 1998 case of United States v. Bajakajian. A narrow 5-4 majority consisting of the unusual coalition of Justice Thomas and four liberals struck down a criminal asset forfeiture on the grounds that the Clause covers forfeitures that are used as "punishment" for an "offense" and apply "only upon a person who has himself been convicted" of the offense in question. This reasoning seems to exclude in rem civil forfeitures, which, technically, are proceedings against the targeted property rather than the owner, and are often applied even against the possessions of owners who have not been convicted or even tried for any offense, simply on the theory that their property was used to commit a crime by someone else. In an opinion written by Justice Anthony Kennedy, the four conservative dissenters in Bajakajian argued that the majority's seeming exclusion of civil forfeitures was a mistake, and that such forfeitures should not "be left completely unchecked by the Constitution." It is not entirely clear whether Bajakajian really does exclude all civil forfeitures, or whether Thomas' opinion for the Court is best interpreted as holding that criminal forfeiture is covered, without making a definitive ruling on the civil kind.