More recently, a former Montana National Guard employee who filed an Equal Employment Opportunity Complaint against the Montana Guard accused Walsh of allowing sex discrimination to occur under his watch.

What makes the plagiarism allegations different from other criticisms is that there is simply no good explanation nor excuse for it. Walsh can reason that he encouraged soldiers to join a good organization that works on their behalf, and he can dispute Major Cindy Neely’s account of her time with the Guard - but there is no good argument for cheating on a research paper in War College.

What would be the honorable thing to do now?

Walsh could resign his Senate seat immediately. Bullock could then appoint a temporary replacement who isn’t running for election, as many Montanans had hoped he would do earlier this year, before he went with Walsh. That replacement could see that the legislation Walsh supported received continued support.

But if Walsh doesn’t do that, at a minimum, he should drop out of the Senate race. He has until Aug. 11 to do so and get his name removed from the ballot, which would allow the Montana Democratic Party to name a replacement candidate by Aug. 20 - just in time to make sure that candidate’s name appears on the ballot.