This is very true. There is no such thing as a federal election in this country, only state elections which pick representatives to the federal government. If POTUS were to issue an executive order which forced states to require a Real ID for all voters it would be immediately struck down by the courts, and I honestly wouldn't blame them. I don't really like the idea of the president unilaterally changing rules about who is and isn't a valid voter, no matter how dangerous voter fraud is. It's an extremely dangerous precedent