The Democrats are descending on Springfield in droves today for their state party’s annual convention, where much of the attention will focus, no doubt, on the expected coronation of Senate hopeful Elizabeth Warren.

But the gathering won’t include one of the most exciting candidates to come out of the party in years: Bill Shein, one of three men running for the party’s nomination for the newly configured 1st Congressional District seat.

Yesterday, Shein announced that he’ll skip the convention in protest of what he called the state party’s failure to stay neutral in the race, instead showing a clear bias for U.S. Rep. Richie Neal, the district’s sort-of incumbent. (Neal is the incumbent in what is now the 2nd District, but his hometown of Springfield moves to the new 1st District starting with this fall’s election. The third candidate for the Democratic nomination is Andrea Nuciforo, a former state senator from Pittsfield who now serves as the register of deeds for the Berkshire Middle District.)

In a letter to party leaders, Shein listed a number of instances of their apparent partiality for Neal, including allowing a Springfield caucus meant to select convention delegates became a de facto “Neal campaign event”; sharing office space with Neal’s campaign; paying for mailings from Neal; and inviting Neal to address the convention but not offering equal time to Shein and Nuciforo.

“It seems that habit, unquestioned tradition, and a lack of State Committee-approved guidelines for the party’s proper role in contested U.S. House races have left you and your staff without clear rules,” Shein wrote. “The party must undertake more rigorous efforts to ensure it treats all candidates in House races equally.”

By skipping the event, Shein will miss the chance to schmooze with the party’s hardest core. But, he wrote, that’s a hit he’s willing to take to make a larger point. “The important principle here—basic fairness and equity in a Democratic Party primary—is more important than any short-term political benefit gained by remaining silent and attending the convention. I believe that given the facts, and the Party’s insistence on proceeding with yet another clear violation of neutrality in a contested race, my attendance would send the wrong message about what is acceptable.”

In a letter to supporters, Shein expanded on his position. “If there’s one thing my campaign for Congress is about, it’s this: We can’t keep doing things the same way. In our politics and elections. In the Congress. In our economy. In our timid approach to addressing climate change.

“In too many areas of American life, we are not living up to fundamental ideals of fairness, justice, and democracy. And this campaign is about standing up, together, and saying, ‘Enough!’”

In the end, skipping the convention might not be the worst move for Shein; after all, the types of folks who attend a party convention are, to a large degree, the folks who are happily benefiting from the current system and unlikely to get fired up about changing it. Shein—whose campaign stops have included union picket lines and neighborhood anti-violence rallies and anti-foreclosure protests, and whose campaign refuses donations over $99—would probably be better off spending his weekend connecting with the kind of people who aren’t included in political conventions—or in the priorities that are shaped there.