Supreme Court Justice Amy Coney Barrett faced a torrent of attacks from right-wing commentators after she voted this week to reject two key pillars of the Trump administration’s agenda, including the effort to end birthright citizenship.

Justice Barrett sided Monday with Chief Justice John G. Roberts Jr. and the court’s liberal minority to reject a push to restrict mail-in voting practices, which he has long blamed, without evidence, as central to his defeat in 2020.

Prominent G.O.P. officials and pundits cast Justice Barrett’s votes as part of a pattern of betrayal of Mr. Trump and the Republican Party. Last year, she was the Republican-appointed justice most likely to be in the majority in decisions that reach a liberal outcome, according to an analysis of her record prepared last year for The New York Times, although that was not true in the current term. She previously cast a deciding vote to block Mr. Trump’s tariffs.

“It turns out that Amy Coney Barrett is a DEI hire, little better than Ketanji Jackson,” Matt Walsh, a right-wing commentator, wrote on Tuesday on social media, referring to Supreme Court Justice Ketanji Brown Jackson, the court’s only Black liberal. “Terrible pick. When’s the last time we had a Republican president who didn’t put a liberal justice on the court?”

Representative Nancy Mace of South Carolina, a far-right firebrand, called for Justice Barrett to “be removed from the Bench.”

A Supreme Court justice can be removed through the congressional impeachment process outlined in the Constitution, requiring a simple majority vote in the House and a two-thirds majority vote in the Senate.

Justice Barrett, whom Mr. Trump nominated to replace Ruth Bader Ginsburg, the liberal justice who died in 2020, has been instrumental in shifting the court to the right. She joined the conservative majority in overturning Roe v. Wade and striking down affirmative action in college admissions, two of the most consequential rulings the court has issued in recent years.

Her vote to uphold birthright citizenship in a decision issued on Tuesday intensified the backlash that had already been building after she had voted one day earlier to uphold a Mississippi state law allowing mailed ballots postmarked by Election Day to arrive as much as five days later.

“A shockingly wrong opinion,” Senator Eric Schmitt of Missouri wrote on social media on Monday.

”Remember Election Day? This disastrous SCOTUS decision, authored by Justice Barrett, guarantees we’ll keep drifting away from it — as our sacred elections get bogged down by endless mail-in ballots and never-ending counts,” Representative Abe Hamadeh of Arizona wrote on X.

Right-wing commentators, including the former Fox News host Megyn Kelly, similarly railed against the conservative justice.

“Amy Coney Barrett is a turncoat,” Ms. Kelly said on her Sirius XM show. “She’s constantly siding with the left.”

While most of the commentary from the right was sharply critical of Justice Barrett, other conservative commentators praised her for what they saw as a principled approach to a job that should rise above the political fray.

“She is a conservative jurist, but she is very independently minded,” the Fox News legal analyst Jonathan Turley said on air on Tuesday. “And I know that’s hard for people to accept.”