The grandson of killed presidential up-and-comer Robert Kennedy lost the Democratic essential to officeholder Senator Ed Markey on Tuesday.
Mr Markey, 74, will represent an additional six-year term in the political decision on 3 November.
It is the first run through an individual from the Kennedy line has been vanquished in a congressional vote in the state.
Mr Kennedy, 39, is at present serving his fourth term in Congress and was viewed as a most loved when he reported he would run for the seat in September a year ago.
He was upheld by House Speaker Nancy Pelosi and conveyed the Democratic reaction to President Donald Trump's State of the Union location in 2018.
In any case, neither his record nor his family's heritage were sufficient to guarantee triumph against Mr Markey, a political veteran who co-composed the Green New Deal with Congresswoman Alexandria Ocasio-Cortez.
"Our development is fuelled by youngsters who are not reluctant to speak more loudly or make adversaries," Mr Markey composed on Twitter after Tuesday's essential.
"This evening's triumph is an accolade for those youngsters and to their vision."
The Kennedy name despite everything opens a great deal of entryways in Massachusetts, however it is not, at this point a brilliant ticket at the polling station.
That is the exercise taken in the most difficult way possible by Congressman Joe Kennedy, whose offer to unseat 74-year-old Senator Ed Markey came up well short on Tuesday.
Kennedy flaunted a celebrated family name and the notoriety for being a rising star among Democrats, yet Markey hosted the sponsorship of the gathering's liberal wing and an especially important support from Congresswoman Alexandria Ocasio-Cortez.
He worked with the New York congresswoman to support the Green New Deal atmosphere plan in Congress, which earned him the energetic help of natural activists.
More youthful voters specifically supported Markey by a huge edge, recommending the individuals who didn't live through the brilliant long periods of the Kennedy faction may see the family not as a confided in political name, yet rather the epitome of foundation benefit and force.
Markey's triumph could likewise be a demonstration of the influence of incumbency, as another congressional veteran, Richard Neal - seat of the ground-breaking House Ways and Means board of trustees - held off a solid test by more youthful liberal challenger Alex Morse.
Lawmakers who are commonly popular and not conflicted in relation to their constituents can be hard to unseat.