The New York Times said in a statement on Tuesday that Jonathan Weisman, a deputy Washington editor of The Times, had been demoted and would no longer oversee the paper's congressional correspondents because he repeatedly posted messages on social media about race and politics that showed what the paper called "serious lapses in judgment."
Mr. Weisman, 53, will lose the title of deputy editor, a designation for Times editors with wide-ranging duties and significant input into news coverage, a spokeswoman for the paper said.
Mr. Weisman met with Dean Baquet, the executive editor of The Times, on Tuesday and apologized, the Times statement said. He will also no longer be "active on social media," the statement added.
In a brief interview after the meeting with Mr. Baquet, Mr. Weisman, who will stay on at the paper as an editor, said: "I accept Dean's judgment. I think he's right to do what he's doing. I embarrassed the newspaper, and he had to act."
The reprimand came amid a broader discussion in the Times newsroom of how the paper covers race and the Trump administration in a polarized time. On Monday, Mr. Baquet led a staff meeting at which a recent front-page headline that generated heavy public criticism was a main topic.
Mr. Weisman, who joined The Times in 2012, was under scrutiny for messages he posted on Twitter on July 31 and Aug. 7. In the July 31 posts, he implied that it was inaccurate to describe certain politicians from urban areas as being representative of the Midwest and the South. He specifically mentioned four Democrats: Representatives Rashida Tlaib of Michigan, Ilhan Omar of Minnesota, Lloyd Doggett of Texas and John Lewis of Georgia. Three of the four are minorities.
"Saying @RashidaTlaib (D-Detroit) and @IlhanMN (D-Minneapolis) are from the Midwest is like saying @RepLloydDoggett (D-Austin) is from Texas or @repjohnlewis (D-Atlanta) is from the Deep South," Mr. Weisman wrote. "C'mon."
Mr. Weisman, who is white, deleted the tweet and a pair of follow-ups after they were criticized as racist on Twitter and in the African-American-focused online publication The Root.
The Times's standards editor, Phil Corbett, advised Mr. Weisman to be more careful on social media, Mr. Weisman said. But on Aug. 7, he ventured into similar territory.
Replying to a Twitter post by the progressive political organization Justice Democrats that included a photograph of Morgan Harper, a candidate the group was backing for a United States House seat in Ohio, Mr. Weisman noted that she would be challenging Representative Joyce Beatty, an African-American Democrat.
Ms. Harper quickly replied to Mr. Weisman's message, telling him, "I am also black."
To that, Mr. Weisman replied, "@justicedems's endorsement included a photo," as if that settled the matter.