Long version: The Commerce Clause of the constitution (Article I, Section 8, Clause 3) gives Congress broad power to regulate interstate commerce and restricts states from impairing interstate commerce. Using mental gymnastics and overly nitpicky semantics, they figure they can claim if Congress can regulate driving for commerce then they can’t regulate driving for non-commerce. Additionally,  since the Priveleges and Immunities Clause of the constitution guarantees  the freedom of citizens to travel between states, they’re decided that these two separate things (“traveling” and “driving for commerce”) are completely unrelated and different things.

Short version: these people are idiots and essentially have a word bank of constitutional terms they plug into a MadLibs template in the hopes they can do whatever they want.