What Kerry is reportedly doing sounds a whole lot like an actual, verifiable act of an American conspiring with a hostile foreign power to thwart an agenda pushed by duly elected U.S. officials, thereby undermining the will of the voters. (To be fair, recent polling shows 56 percent of surveyed voters support the Iran deal. But elections do matter, and all that).
As to whether any of this amounts to a violation of the Logan Act, let’s leave that answer to the legal expert quoted by the Boston Globe, who said, “The act only applies to conduct that is designed to ‘defeat the measures of the United States’ or influence the conduct of foreign governments. If all Kerry is doing is working to keep in place something that’s still technically a ‘measure of the United States,’ I don’t see how the statute would apply even if someone was crazy enough to try it.”
Then again, this interpretation implies that private actors who help the administration achieve its goals of changing current foreign policy would be violating the Logan Act. So go figure.