A subpoena duces tecum requires the witness to produce a document or documents pertinent to a proceeding.
We the People want to know who is behind Cotton's egregious and false letter to Iran. We think he has violated his oath of office. Being influenced by right-wing pundits and lobbyists to commit such a gross and false breach of international protocol should be punished.
Also, all 47 Senators may have violated 18 USC § 954- False statements influencing foreign government.
"There’s a reason for ...suspicion. Kristol’s Emergency Committee for Israel gave Cotton nearly $1 million in his race for the Senate just five months ago. Cotton also got $165,000 from Elliott Management Paul Singer’s hedge fund. Singer is the billionaire who is trying to stop Obama’s Iran talks."- mondoweiss.net