"Bullies may land a punch", Kennedy said.
Prior to serving in Congress, Kennedy attended Stanford University as an undergraduate and spent two years serving in the Peace Corps in the Dominican Republic.
In his official Democratic response speech, which emphasized the outrage and protest over President Donald Trump's policies, Kennedy channelled the anger and energy of the president's many opponents, while also highlighting their accomplishments.
You swarmed Washington previous year to ensure no parent has to worry if they can afford to save their child's life.
They said the President will "unifying" and will speak "from the heart", and "the tone will be one of bipartisanship and it will be very forward looking". And it served as a fitting backdrop Tuesday night for the Democratic view that Trump has presided over an economy that benefits the nation's wealthy elite but has left the working class behind.
This will Mr Trump's first State of the Union address - the traditionally annual message covering global and domestic issues and the budget. Kennedy made headlines when he dubbed the Republican healthcare bill an "act of malice".
A graduate of both Stanford and Harvard, Kennedy served as an assistant district attorney in MA before serving in Congress.More news: Waymo buys thousands more Chrysler vans for driverless service
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You battle your own quiet battles every single day.
Kennedy's may be an unfamiliar face to many, and that's partially by design. But Kennedy's profile has risen a bit due to his forceful denunciations of the Republican health care plan. And probably most important for the sake of Democratic unity: Kennedy isn't immediately angling for a higher office, which meant that viewers could take the address for what it was, a smart speech with no obvious personal agenda.
Kennedy serves on the Energy and Commerce Committee and has sponsored legislation to boost the manufacturing sector.
Noting that "hatred and supremacy" are "proudly marching in our streets", Russian Federation is "knee-deep in our democracy", and the Justice Department is "rolling back civil rights by the day", Kennedy said that the administration "isn't just targeting the laws that protect us - they are targeting the very idea that we are all worthy of protection".
Image copyright Getty Images Image caption His grandfather, Senator Robert Kennedy, was killed during a run for president in 1968 What kind of politician is he?
But the speech - which was broadcast in front of an audience inside a Fall River technical school - and indeed the representative himself ended up being the flawless fit.
Kennedy, the grandnephew of the nation's 35th president, leaned heavily on issues of civil rights, lending shout-outs to the MeToo activists combating sexual harassment, the BlackLivesMatter activists fighting racism, a transgender student who suffered bullying and the so-called "Dreamers", young immigrants brought to the country illegally as children.
According to an article in the Boston Globe, King, 37, enlisted in the Army right after graduation from Cape Cod Tech and has been deployed to Afghanistan three times.