The Colorado congresswoman, one of just 200 lawmakers able to attend the president’s Joint Address to Congress, was seen shaking her head.
NBC News Capitol Hill correspondent Kasie Hunt was one of a number of people to point out that Ms Boebert also did not clap or stand up when Mr Biden urged Americans to get vaccinated.
Most of Ms Boebert’s Republican colleagues stood and applauded.
Ms Hunt tweeted that the lawmaker appeared to be texting, noting shortly afterward that she was still typing on her phone.
With President Biden still speaking, Ms Boebert replied on Twitter to correct her: “*Tweeting.”
On her official Twitter account, Ms Boebert did indeed live-tweet her reaction to the speech: “What I want to hear in Biden’s speech is how to solve the border crisis,” she wrote. “What I will hear are plans to spend trillions of dollars and raise taxes.”
She added: “What I don’t want to hear are disingenuous calls for unity from this authoritarian leader and his radical administration.”
At one point she tweeted: “Is it me or is Biden talking about a lot of problems that were created in his nearly 50 years in office.”
On gun control, she wrote: “Will Joe Biden start his gun control crusade by investigating Hunter?”
Meanwhile, on her personal Twitter account, Ms Boebert posted: “You just heard Joe Biden ramble on for an hour about how government is the solution to everything. It is not.”
She followed that by asking for donations to her campaign.
Ms Boebert later wrote: “We, the people, have had enough of big government.”
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