Holder is all bark. He has zero authority to challenge a state law of any sort. Until he sends a goon to violate it and said goon gets arrested Holder has what he likes to call “no standing”. He ought to read his own mail and STFU until he stirs up a legitimate/fake complaint. But I want to know who the federal genius will be willing to risk time in a Kansas jail?-—by pushing his luck in Kansas without letting the local county Sheriff know what he’s up to. County sheriffs do indeed have authority to ride herd on out-of-line fedz.
Holder has full authority to challenge state laws that he feels contradicts state laws. Who do you think represents the United States in the court system in litigation? It is the US Attorney whose ultimate boss is Holder.
Also, in real life and under how the law actually works it would be the state agent in jail if they tried to interfere with federal agents performing federal duties.
Lastly, federal agents receive their jurisdiction and authority from Congressional statutes and not the local sheriff. While the federal agents cannot force the local sheriff to enforce federal laws, the local sheriff cannot lawfully impede or interfere with a federal agent enforcing federal law. A sheriff receives his authority from a state constitution or state statute but NOT the federal government. Therefore, he has no lawful purview or authority in federal matters.