Banking. Money crosses state lines which makes it fair game under the commerce clause. There's only 50+ years of court cases on the subject.
The precious CRA is an oft cited law as to why we need expansive interpretation of that clause (as without it CRA as we know it would be finished), the sooner SCOTUS crushes the CRA the sooner we can finally crush the rest of the civil rights violating overreaches of the prior commerce clause interpretations.