“Google's control over what people hear, watch, read, and say is unprecedented,” Sen. Ted Cruz, R-Texas, the chair of  the Senate Judiciary Committee, said. “Google can, and often does, control our discourse.”

Cruz added: “The American people are subject to overt censorship and covert manipulation” by Google’s algorithm.

Google’s vice president of global government affairs and public policy, Karan Bhatia, defended the tech giant – arguing that the company has no political bias and does not monitor content posted on its platforms. Bhatia noted that the company does censor or take down some content, but denied that there was any political motivation behind that.

“We work hard to fix our mistakes,” Bhatia said.

“But these mistakes have affected both parties and are not a product of bias.”

He added: “We are not censoring speech on our platforms…We do have community guidelines against uploading, for example, videos that have violent imagery.”

Later in the hearing, Cruz criticized Google’s executives for their broad support of former Secretary of State Hillary Clinton during the 2016 presidential election, saying that 88 executives at the company contributed to her campaign.

“You know how many contributed to Donald Trump?” Cruz asked. “Zero, goose egg.”

Cruz’s Democratic counterparts on the committee defended the tech giant against the bias accusations, but didn’t spare the company when it came to criticism that it does little to remove violent and disturbing imagery and videos from its platforms.

The Democrats criticism was bolstered by the appearance in the audience of Andy Parker, whose 24-year-old daughter, Alison, a television reporter in Virginia, was shot and killed on live TV in 2015. Parker has worked to press Google to remove all footage of his daughter’s murder from its platform, with Google informing him that he could flag the content for removal.

“Why should a father have to search for, flag, and watch videos of his daughter’s murder?” Sen.

Mazie Hirono of Hawaii, the ranking Democrat on the committee, asked.

Bhatia argued that the company is working to remove the videos but has so far been unable to take down every one.

Google’s appearance on Capitol Hill came hours after senators grilled Facebook on its plans to launch a new digital currency when it was still battling problems with privacy and other issues during a Senate Banking Committee panel.

Arizona Republican Sen. Martha McSally said she doesn't trust Facebook because of repeated privacy violations and "repeated deceit."

Facebook executive David Marcus argued the company wants to innovate on behalf of its users.

He said if another country were to build a successful digital currency first, the system might be out of reach of U.S. regulations and sanctions.

The Associated Press contributed to this report.