The Massachusetts Democrats’ link to a student group’s smear against Holyoke Mayor Alex Morse raised serious concerns about the state party’s behavior amid an important election for the 1st Congressional District.

An internal report demanded by some party members has corroborated those concerns, and now begs the question of what the state party will do to repair and maintain its integrity.

Less than a month before last year’s Democratic primary in which Mr. Morse was challenging incumbent Rep. Richard Neal, the race was rocked by allegations of sexual misconduct against Mr. Morse. The accusations were leveled by students within the University of Massachusetts Amherst chapter of the College Democrats of Massachusetts. Reporting by The Intercept soon revealed, however, that the allegations were part of a year-old plan hatched by the student group to “sink his campaign.” There has been no evidence linking Rep. Neal or his campaign to the students’ plot or the allegations.

Follow-up reporting by both The Intercept and The Berkshire Eagle subsequently revealed the involvement of Massachusetts Democratic Party leadership in conversation with the student group about dissemination of a letter written by the College Democrats detailing their unsupported allegations that the student group then sent to several news media outlets as well as Mr. Morse.

The letter had its drafters’ desired effect, roiling the race just ahead of the first debate and weeks before Election Day. It was only afterward that the UMass Amherst Democrats apologized to Mr. Morse, an openly gay man, for directing the campaign’s spotlight onto his sex life based on salacious and baseless accusations. Furthermore, an internal investigation at UMass Amherst, where Mr. Morse was an adjunct professor, determined that he did not, despite the letter’s intimations, violate university policy regarding teacher-student relations.

Unresolved issues remain, however, within Massachusetts Democratic Party leadership, as pointed out by an internal report from attorney Cheryl Jacques, a former Democratic state senator. The mountain of evidence in the report is damning. State party leadership helped along the letter that sought to malign a congressional candidate against the advice of an attorney they consulted, who suggested the letter’s claims were shaky at best. Party officials referred the College Democrats to party-connected lawyer Jim Roosevelt for counsel, who made some minor edits to their letter. Ms. Jacques noted in her report that two College Democrats corroborated each other’s account that Mr. Roosevelt then told the students to leak the letter. Mr. Roosevelt denies this. Eventually the letter was leaked to several media outlets.

The internal report also found that state party leadership was dishonest about ongoing contact with the College Democrats in the wake of the letter’s release and the ensuing news media firestorm. Party leadership lied when it claimed “no further involvement” with the College Democrats once the students were referred to legal counsel. Democratic State Committee Executive Victoria Martinez also lied when she publicly denied instructing students to destroy evidence of communications with the state party.

Furthermore, Ms. Jacques’ report suggests that Democratic State Committee Chairman Gus Bickford violated the party’s own bylaws in communications with the students: “Gus’s admission ... indicates to me that he was encouraging the students to talk to the reporter on the record and to do so prior to the election,” read the internal report’s key findings. “I conclude that Gus’s actions violated DSC Bylaw section 2(d) which prohibits staff of the DSC from participating in a contested Democratic Primary campaign.”

While Mr. Bickford handily won reelection as party chairman shortly after the internal report’s commission, some within the party understandably seek a reckoning. State party officials would hopefully agree that their own rules exist for a reason. They should see that those who break them — even their most powerful members — are held responsible.

If Mr. Bickford has any respect for the integrity of his party as a democratic institution, he should resign.

Further, the party’s leadership should acknowledge its significant missteps here and demonstrate what they’re doing to ensure it doesn’t happen again.

A contentious election season has just reminded us how important — and delicate — some of our democratic frameworks are. They require vigilant protection, and that means holding accountable those at the top. That’s as true at the state level as it is at the federal level.

The Massachusetts Democrats’ party leadership owe a lot more to the constituents they lied to and the democratic process they apparently helped to undermine.