And not every Democratic leader here is unsettled by the outbreak of primaries.

“I may be in the minority, but I like the idea of competitive primaries,” said former Gov. Deval Patrick, who claimed the Democratic nomination for the state’s top job as a political outsider . “Every member of our delegation knows that nobody is entitled to these jobs. Competition for office is the way it’s supposed to work.”

Mr. Patrick, who, like many other Democratic officials here, has been lobbied for support by Mr. Markey, said he would stay out of a Kennedy-Markey race. But in an ominous sign for Mr. Markey, other Massachusetts Democrats who have announced their support for him sounded less committed when asked what they would do were Mr. Kennedy to run.

“I go way back with the two of them,” said Mr. Neal, calling them “both very good legislators.”

Mr. Walsh was even more equivocal about his preference. “I’m not going to speculate, let’s see what happens,” he said.

Of the primary battles for House seats, none may prove to be as competitive as the one between Mr. Neal, 70, and Alex Morse, the 30-year-old mayor of Holyoke.

“There’s an urgency to this moment that isn’t matched by the current representative in Congress,” said Mr. Morse, criticizing Mr. Neal for opposing the Green New Deal and Medicare for All and for taking P.A.C. money.

But Mr. Neal argued that most of his constituents were happy to be represented by the chair of perhaps the most influential House panel, and he reeled off the millions of dollars he had brought back home to Western Massachusetts while highlighting the legislation he has helped steer to passage this year.

And demonstrating that he would not be caught unprepared, Mr. Neal lashed back at Mr. Morse, noting that the Holyoke schools had been placed in state receivership on his watch.