Tom C. Clark,
Hamm v. City of Rock Hill, 379 U.S. 306 …
“ In our view Congress clearly had the power to extend immunity to pending prosecutions. Some might say that to permit these convictions to stand would have no effect on interstate commerce which we have held justified the adoption of the Act. But even if this be true, the principle of abatement is so firmly imbedded in our jurisprudence as to be a necessary and proper part of every statute working a repealer of criminal legislation. Where Congress sets out to regulate a situation within its power, the Constitution affords it a wide choice of remedies. ”
