One of the last Democratic congressional primaries of this election cycle is also one of its most consequential.

Holyoke, Massachusetts, Mayor Alex Morse , 31, is taking on Rep. Richard Neal , chairman of the House Ways and Means Committee, on Tuesday in the Democratic primary for Massachusetts 1st Congressional District.

As head of the panel in charge of taxation and virtually all social program spending, Neal, 71, is one of the most powerful Democrats in Congress. Progressives have faulted him for everything from dragging his feet on demanding President Donald Trump s tax returns and his role in stalling bipartisan legislation to end surprise medical billing. In the current election cycle, he is the Houses biggest recipient of donations from corporate political action committees many of them from health care companies, the fossil fuel industry and Wall Street firms with lucrative policy interests at stake before Neals committee.

There are myriad factors at work in the races potential outcomes, including local regard for Neal and concern about losing his clout in Washington. The former mayor of Springfield, who has represented central and Western Massachusetts since 1989, is not beset by the same challenges of other ousted incumbents, such as Reps. Eliot Engel and Joe Crowley of New York. Engel, Crowley and others could be credibly accused of losing touch with their constituents, which is, by all accounts, a tougher sell against Neal.