Nebraska Sen. Ben Sasse (R) was widely criticized Friday night when he failed to immediately call out HBO "Real Time" host Bill Maher after the liberal talk show host used a racial epithet.

During a segment on "Real Time" Friday, Sasse invited Maher to visit Nebraska to help work in the fields there. But Maher crossed a line when he jokingly declined Sasse's invitation and invoked the "n-word," saying he's a "house n***er" and doesn't work in fields.

Sasse, obviously uncomfortable with what Maher had just said, appeared to be in shock, but continued the segment without stopping to confront Maher over his use of the socially prohibited word.

Sasse's failure to immediately rebuke Maher is what many criticized him for. Some liberals, like MSNBC host Joy Reid and Symone Sanders, the former press secretary for Democratic presidential candidate Sen. Bernie Sanders (I-Vt.), took the criticism a step further and seemingly rebuked Sasse as if he said the word.

In a series of tweets, Reid said that Sasse's immediate thoughts of Maher using the "n-word" was how it will affect his future presidential aspirations.

Sanders, on the other hand, said Sasse's failure to immediately react harshly to Maher was evidence of a larger issue in the Republican Party.

"Ben Sasse on #RealTime is a clear demonstration of the disregard GOP has for Black ppl -- One of many reasons they struggle w/Black voters," she tweeted.

While most others, especially conservatives like Mary Katherine Ham and Dana Loesch, defended Sasse, the Republican senator took to his Twitter account early Saturday to respond to the ensuing firestorm.

Sasse said that while he is staunch supporter of the First Amendment and believes comedians have the right to use socially prohibited words, he regrets not rebuking Maher during the interview. Sasse said that his obvious "cringe" wasn't enough.

In the wake of Maher's sin, many progressives and liberals are calling on HBO to remove Maher from his show.

"His show needs to be cancelled," wrote a reporter at The Root, a news and opinion website that focuses on issues that matter to the black community.

Neither HBO nor Maher has made a public statement in the wake of the outrage.