“Roseanne,” featuring a working-class family of five and assorted relatives, returned to the air this week more than two decades after it ended its run. The lead actress’s character plays a backer of Mr. Trump. (Roseanne’s TV sister, Jackie Harris, by contrast, supports Hillary Clinton, though ultimately voted for Jill Stein.)

Ms. Barr herself has been a vocal defender of Mr. Trump.

In an interview with The New York Times published Tuesday, Ms. Barr said that she decided to turn her character, Roseanne Conner, into a Trump supporter because she felt it was an “accurate portrayal” of the political preferences of many working-class Americans.

“I just wanted to have that dialogue about families torn apart by the election and their political differences of opinion and how we handle it,” she said. “I thought that this was an important thing to say at this time.”

Ms. Barr defended the president at several points in the interview, objecting to a suggestion that he opposes many of the views that she and Roseanne Conner have espoused over the years, like support for abortion rights, same-sex marriage and organized labor.

Mr. Trump used to back abortion rights before running for president as a Republican, but he has never supported same-sex marriage.