Senator Katie Britt of Alabama criticized President Biden as ill-equipped to lead the country in a speech on Thursday that served as both a rebuke to his State of the Union address and an introduction to the nation by a politician many Republicans have seen as a rising young star.
“Our commander in chief is not in command,” Ms. Britt said in the Republican Party’s official response to Mr. Biden’s speech. “The free world deserves better than a dithering and diminished leader.”
Ms. Britt, 42, delivered an uneven speech, toggling between a wide, often strained smile and a furrowed brow paired with a fierce glare as she delivered ominous warnings about illegal immigration.
She spoke from the kitchen table at her home in Montgomery, Ala., an unusual setting aimed at underscoring her argument that Mr. Biden represents a threat to prosperity for American families. But the backdrop seemed to confuse viewers on social media, where Ms. Britt was mocked by some for using a dramatic, breathy voice to deliver critiques of the president.
“Under his administration, families are worse off — our communities are less safe, and our country is less secure,” she said. “I just wish he understood what real families are facing around kitchen tables just like this one.”
Ms. Britt has been mentioned as a potential running mate for former President Donald J. Trump, who has all but locked up his third consecutive Republican nomination.
She won her first elected office in 2022, becoming Alabama’s first female senator and the youngest Republican woman elected to the chamber. Speaker Mike Johnson noted in announcing that she would give the State of the Union response that she was the “only current Republican mom of school-age kids serving in the Senate.”
Her selection made for a stark contrast with Mr. Biden, 81, the nation’s oldest president, who is facing skepticism within his party about whether he is too old for a second term.
She also symbolized the latest Republican attempt to broaden the appeal of a party represented overwhelmingly in Washington by white men.
Last year, the Republican response was given by Gov. Sarah Huckabee Sanders of Arkansas, a former Trump White House press secretary, who became the nation’s youngest governor when she took office early last year. The previous Republican responses to Mr. Biden’s speech came from Gov. Kim Reynolds, Iowa’s first female governor, and Senator Tim Scott of South Carolina, the only Black Republican in the chamber.
Ms. Britt repeatedly brought up families and her children in her speech.
“The country we know and love seems to be slipping away — it feels like the next generation will have fewer opportunities, and less freedom, than we did,” she said. “I worry my own children may not even get a shot at living their American dreams.”
Ms. Britt is, at first glance, an unlikely vice-presidential contender for Mr. Trump. She rose to the Senate within the business-friendly establishment wing of the Republican Party that he has driven from power.
She served as chief executive of the Business Council of Alabama, the state’s chamber of commerce, and as a former chief of staff to former Senator Richard Shelby, Alabama’s longest serving senator.
But Ms. Britt has been on Mr. Trump’s radar since August 2021, when she was at the end of a receiving line to shake the former president’s hand during a Republican gathering in Alabama.
Ms. Britt, then a candidate for Senate, introduced the former president to her husband, Wesley Britt, noting that he played professional football for the New England Patriots, whose billionaire owner, Robert Kraft, is close to Mr. Trump, according to two people familiar with the exchange.
Even though Mr. Trump had already endorsed her primary opponent, Representative Mo Brooks, Ms. Britt would tell Mr. Trump that she deserved his endorsement instead.
Seven months later, in March 2022, Mr. Trump withdrew his endorsement as Mr. Brooks dropped in the polls. He backed Ms. Britt, calling her “an incredible fighter for the people of Alabama,” less than two weeks before her runoff election with Mr. Brooks in June.
Democrats seized on Ms. Britt’s selection for the Republican response as they try to make abortion rights and women’s issues central campaign topics.
Last month, the Alabama Supreme Court ruled that frozen embryos should be considered children, imperiling access in the state to fertility treatments like in vitro fertilization. Ms. Britt, who has said that she believes life begins at conception, came out in support of access to I.V.F. after the ruling.
Ms. Britt, along with most Senate Republicans, voted this year against a breakthrough bipartisan bill to crack down on immigration while providing new aid to Ukraine.
On foreign affairs, she argued that Mr. Biden’s “strategy of appeasement” had led to chaos and turmoil around the world.
Ms. Britt, along with a small majority of Republicans, voted against an aid package to Ukraine, Israel and Taiwan that ultimately passed the Senate.