As Mathew states, treason is the only crime written in the US Constitution and specifies that two witness are required.
Daniel's speech when he runs for sheriff is reminiscent of Mark Antony's speech about Brutus in Shakespeare's Julius Caesar. Mark Antony peppered his speech with the phrase "but Brutus is an honourable man" and Daniel does the same, repeating the line "but Hank is a good man". In both speeches, the men cast doubt about the actual intentions and behaviour of their opponent.