Americans will hear a Democratic congressman with a familiar name give his party’s response to President Donald Trump’s State of the Union address on Tuesday night, but for most, it won’t be a familiar face.

Rep. Joe Kennedy III, 37 years old, has been chosen to deliver the official televised response, as party leaders turn to a young third-term congressman with a famous last name who isn’t well known outside of Massachusetts.

Some Democrats see Mr. Kennedy, the grandson of Sen. Robert F. Kennedy and grandnephew of former President John Kennedy, as an up-and-coming future leader in a party where many of its senior officials are part of an older generation.

“People know the Kennedy brand, they know the name, but they don’t know Joe Kennedy. This is an opportunity for people to get to know who he is and what’s he’s about,” said New York Rep. Joe Crowley, chair of the Democratic caucus, in an interview.

Mr. Kennedy will speak from a technical school in his district. He invited a transgender infantry soldier to attend the speech in Washington, a protest against the Trump administration’s proposed transgender military ban.

As President Trump prepares to deliver his State of the Union address to Congress on Tuesday night, WSJ's Gerald Seib tells us what to watch out for. On the top of the list: what the president says on immigration, trade and North Korea. Photo: Getty

On the choice of the Fall River, Mass., technical school, Mr. Kennedy said the setting “aimed to highlight the resilience and ingenuity that makes our nation strong.”


“I’m just hoping I can make it on and off the stage without tripping, dehydrating or ruining my career. And that my six-week-old son will let me sleep for a couple hours tonight,“ Mr. Kennedy said in a statement Monday. ”On a serious note, I’m grateful for the privilege and focused on offering the country a compelling alternative to President Trump’s agenda.”

The pick of Mr. Kennedy didn’t sit well with all Democrats. Progressives criticized what they see as Mr. Kennedy’s overly cautious approach on health care and legalizing marijuana, as well as what they termed his hawkish foreign policy stances.

“Joe Kennedy is an establishment pick, which is tone deaf after the 2016 rejection of the Bush and Clinton dynasty,” said a Democratic lawmaker, referring to the unsuccessful runs of Hillary Clinton and Jeb Bush.

Republicans hit on similar themes, saying the pick of a Kennedy showed that the Democrats were out of touch with the electorate.


“Honestly, I can’t think of a time since the Declaration of Independence that Americans were more distrustful of aristocracy,” said Josh Holmes, a former aide to Senate Majority Leader Mitch McConnell (R., Ky.). “The fact that Democrats moved from a Clinton back to another Kennedy for this response tells me they’ve learned absolutely nothing from the last election.”

Mr. Kennedy’s colleagues say he has put his head down and worked hard since he was elected and not taken an easy ride on the family name.

“It’s hard for me to tag him with any label,” said Rep. Marc Veasey (D., Texas). “Sometimes you think you are talking to an old sage that has seen it all, very worldly, and then you quickly remember that Joe is still in his 30s. Just incredibly wise beyond his years.”

Party leaders in both chambers are in charge of the selection. Senate Minority Leader Chuck Schumer (D., N.Y.) took the lead last year, and this year House Minority Leader Nancy Pelosi (D., Calif.) led. She knew exactly who she wanted. “Throughout this process, he was the clear favorite,“ said Drew Hammill, Mrs. Pelosi’s spokesman. ”There just couldn’t be a clearer distinction than between Joe Kennedy and Donald Trump."


Mr. Kennedy has stood with Democrats in opposition to Mr. Trump’s policies, but he didn’t join 120 of his Democratic colleagues last year in signing onto a Medicare-for-all bill and has voted against marijuana legalization.

Marissa Barrow, a spokeswoman for the Progressive Change Campaign Committee, said that as a rising star in the party, Mr. Kennedy has a choice. He can represent the Democratic establishment or “he could be a star for the ascendant Elizabeth Warren wing of American politics that unites voters of all political stripes around a vision of fighting for working people to have better lives.”

Mr. Kennedy’s office said the lawmaker was unavailable for an interview ahead of his speech.

The selection of the State of the Union response speaker is seen as a way to give an up-and-coming lawmaker a national stage. It has gone better for some than others.


When Democrat Barack Obama was president, Sen. Marco Rubio (R., Fla.) awkwardly stopped to drink water during his rebuttal speech. For others, like former South Carolina Gov. Nikki Haley, the speech helped them become a national name. Ms. Haley is now U.S. ambassador to the United Nations.

As Mr. Kennedy speaks, other Democratic allied lawmakers are crafting their own responses as well. Sen. Bernie Sanders (I., Vt.), a favorite of progressives, will give his own response to Mr. Trump’s speech on his social media channels. And Rep. Maxine Waters (D., Calif.) will respond on the BET network. Last year, Ms. Waters became a star of the so-called resistance movement, dubbed “Auntie Maxine."

Write to Natalie Andrews at Natalie.Andrews@wsj.com