I sincerely hope...

that Congressman Kennedy takes a pass on challenging Senator Ed Markey in next year's state primary.
I like Ed, he is a bit of a blatherskite but his heart is bolted in the right spot and he has waited a long long time for his Main Chance in Politics, he has a right to a Uncontested Victory Lap.  Indeed though, what are these "rights" in an age of Rising Primary Challenge Politics?  Both Congresspersons Moulton and Pressley owe their current preeminence to a willingness to aggressively challenge a democratic incumbent in a primary.  Sooner or later this motif was gonna assert itself at the senatorial level, it was only a matter of time.
Lets face it though, even though the Kennedy Vibe is to "hire the best & smartest", there is always cadre of shit-stirrers surrounding politician in question urging him or her to Greater Glory. This is where we get Edward Maximus' abortive 1980 Campaign for the Presidential Nomination or Joseph P. Kennedy II's stillborn Gubernatorial Bid, all the work of shit-stirrers.  JKIII is no different in that respect, that crowd around him may also be unconvinced that Senator Warren can go all the Way to the White House, therefore its either overthrow Ed or sit on their hands for six more years.
Supposedly the poll shows Kennedy leading by a narrow margin, both candidates are flush with cash, but Markey already has a statewide organization and pockets bulging with political IOUs.  Assuming he is willing to fight for it, this won't be a cakewalk for Kennedy, who'd potentially be terminating his political career prematurely if Markey prevailed in the Primary.
I say give it a pass Congressman the Commonwealth's democrats need to concentrate on volunteering in NH, fundraising, selecting a winning Presidential Nominee and most of all beating Donald Trump...