Senator Tom Cotton and 46 others have written an Open Letter to the Iranian Government as an attempt to influence and interfere with our President's current negotiations.
This is a violation of the Logan Act, a United States federal law that forbids unauthorized citizens from negotiating with foreign governments. It was passed in 1799 and last amended in 1994. Violation of the Logan Act is a felony, punishable under federal law with imprisonment of up to three years.