From boston.com:
From the beginning of the race, local politicos have speculated publicly and privately that Kennedy’s decision to challenge Markey was at least partly an effort to get ahead of running in a potentially tougher open primary in a field including other rising Democratic stars, such as Pressley, the state’s first Black congresswoman.
Kennedy’s campaign is adamant that’s not the case, citing the urgency of addressing systemic inequalities that have reached a breaking point.
But in a New York Times article Monday, Suffolk County District Attorney Rachael Rollins — who is supporting Markey in the Senate primary — gave the theory its most prominent voice, suggesting that Kennedy was running this year to avoid a future Senate primary race against Pressley.
“I’d be shocked if Ayanna didn’t jump,” Rollins told the Times.
For her part, Pressley is not ruling out the possibility of running for higher office, even if there are far more pressing issues at hand.
https://www.boston.com/news/politics/2020/09/01/joe-kennedy-ayanna-pressley-senateFrom
The New Republic:
Perhaps the least appreciated player is freshman Representative Ayanna Pressley, who has risen to Kennedy-like celebrity among progressive activists over the last few years. Massachusetts has always punched above its weight in producing national political figures (remember that Warren was one of four locals who ran for president this cycle), and Pressley is destined for statewide office at some point in the future. Kennedy would clearly prefer to establish himself as the Democratic Party’s future before she gets the chance to squeeze past him.
https://newrepublic.com/article/159178/joe-kennedy-markey-2020-ayanna-pressley