Recently, a few aspiring 2020 Democratic Presidential candidates (specifically Kamala Harris and Elizabeth Warren) have spoken out in favor of "reparations" to black people for American Slavery, which was abolished over 150 years ago.
Mirriam Dictionary defines a "Bill of Attainder" as:
a legislative act that imposes punishment without a trial
Bills of Attainder are specifically prohibited by the US Constitution in Article 1, Section 9.
Of course, the idea behind banning Bills of Attainder was to prevent abuse whereby legislatures would target groups of people and pass laws summarily punishing them for perceived actions or transgressions.
Would any Bill establishing "slavery reparations" not have to be considered an illegal Bill of Attainder since they specifically target non-black people and slate them for punishment without a trial?