Challenged in the SCOTUS for what? For the mental state required being less than "intent"?

Crimes not requiring intent or "knowing" violations are literally EVERYWHERE and are as prevalent as the air we breathe.

The Model Penal Code, which is the criminal code adopted by many states, describes mental states required for criminal culpability. (The common law is the same in this regard, I'm just too lazy to go find a case that teaches about the basics of mental states).

Model Code Penal § 2.02 states:

General Requirements of Culpability. (1) Minimum Requirements of Culpability. Except as provided in Section 2.05, a person is not guilty of an offense unless he acted purposely, knowingly, recklessly or negligently, as the law may require, with respect to each material element of the offense.

Heck, some crimes are even based on strict liability, meaning you don't even need to be negligent. Historically, statutory rape has been a strict liability offense, meaning you could be convicted of the felony of statutory rape even if you reasonably believed the victim was old enough for sex.