It’s probably not entirely a coincidence that the two members of the Massachusetts congressional delegation who are boycotting Friday’s presidential inauguration happen to represent the state’s two most Democratic-leaning districts (per the Cook Political Report’s ratings). Katherine Clark of Melrose was the very first member of Congress to announce her non-attendance, last week; some 50 others were on the bandwagon when Somerville’s Michael Capuano added his name Wednesday.

Both Capuano and Clark can be a little, shall we say, pugnacious. Clark, in just her second term, helped plan and execute last summer’s congressional sit-in to protest the lack of gun-control legislation. Capuano, with a long history of scrappy politics, is rumored to be contemplating the end of his nearly two-decade run in the U.S. House of Representatives.

When Clark, working with Georgia congressman John Lewis, pulled off that sit-in stunt, most of her Bay State colleagues were quick to join them. Not so with the Trump inaugural boycott, even though Lewis again took the symbolic lead—prompting a nasty Twitter attack on the civil-rights icon, from the President-elect, which deeply offended many of them.

Listen to WGBH All Things Considered's host Barbara Howard's interview with Congresswoman Katherine Clark below. 

I think two things have been holding them back. One is Lewis’s explicit linking of his decision to boycott with his belief that Trump is not “a legitimate President,” due to the alleged Russian meddling.

That’s a bridge too far for most voters, and a grave offense to many. Individual members can, and have, expressed their own, differing reasons for boycotting. But, in the court of public opinion, the boycott is inextricably linked with Lewis, and by extension his comments.

That’s not a helpful association for representatives of the state’s more purple districts, including Bill Keating’s Cape Cod, Seth Moulton’s North Shore, and Niki Tsongas’s Merrimack Valley. It’s also potential baggage for anyone contemplating a future state-wide campaign, as Joe Kennedy III may have in his future plans.

All that political calculation aside, however, the other issue is a genuine belief that many public officials hold in the importance of the symbolic trappings of the great American experiment in democratic self-governance.

After all, we are learning through Trump’s counter-example that many of our system’s greatest protections lie in norms—most notably the peaceful transfer of power, but also financial conflict-of-interest disclosure and access of press coverage—that exist by more by mutual consent than enforcable law.

It might seem corny, or perhaps sheep-like, but many elected officials take seriously the symbols and rituals of the American political system—especially veteran pols, including Capuano, Stephen Lynch, Jim McGovern, and Richie Neal.

Bear in mind that those four all had to stand there, as Nancy Pelosi handed the Speaker’s gavel, and all the power it represents, to their political enemy John Boehner in January 2011. And as they watched, they could remember their Republican colleagues watching, four years earlier, as their party transferred that same gavel to Pelosi.

So, I’m not surprised that the Massachusetts delegation has felt a strong obligation to honor the peaceful transfer of power, despite their concerns with the man receiving that power.

But, I’m also not shocked that after a week hearing from constituents in liberal Somerville during the House recess, Capuano decided to join the boycott anyway.