WASHINGTON -- The special House committee investigating abortion providers got off to a contentious start Wednesday as Democrats on the panel objected to the GOP’s subpoenas of the names of doctors, medical students and researchers involved in performing abortions or conducting fetal tissue research.

The special committee, now called the Select Investigative Panel on Infant Lives, was convened last year by Republicans following the release of a series of undercover videos by anti-abortion activists showing Planned Parenthood staff discussing the donation of fetal tissue for research.

Marsha Blackburn (R-Tenn.,) said the sting videos "revealed that something very troubling is going on related to fetal tissue and research."

"There is something going on, something that deserves investigating and that demands our best moral and ethical thinking," Blackburn said. She argued that Wednesday's hearing was about bioethics and not about "election year politics."

Republicans and the Center for Medical Progress, which made the videos, claim that Planned Parenthood was illegally profiting from the transfer of the tissue, which Planned Parenthood has denied. Multiple congressional committees and states have investigated the matter and found no evidence of wrongdoing.

The founder of the anti-abortion Center for Medical Progress, David Daleiden, was indicted by a Texas grand jury in January after the jury cleared Planned Parenthood.

“They are persisting in moving forward as if the maker of the tapes had not been indicted and discredited and as if the investigations of the committees and the states did not happen at all,” Rep. Jan Schakowsky (D-Ill.), the committee’s top Democrat, told reporters.

The hearing was held at the same time as the Supreme Court heard oral arguments across the street in a major case that could shut down abortion clinics statewide.

Rep. Jerrold Nadler (D-N.Y.) immediately asked Blackburn, the committee chair, to explain why Republicans had requested the names of doctors, medical students and researchers in subpoenas sent to hospitals, abortion clinics, fetal tissue procurement companies and academic institutions.

“To date, you have refused to explain how this information is pertinent to this investigation,” Nadler said, arguing that equivalent information could be obtained from representatives of the institutions receiving subpoenas. “Nor should we proceed with dangerous subpoenas that endanger the lives and physical safety of patients, providers and researchers in a way that could make this committee complicit with any physical assaults or murders of these people.”

Blackburn told reporters after the hearing that the majority would “do everything possible to protect names and identities … we will do redactions as necessary to protect privacy.”

But, as Schakowsky, the committee’s ranking member pointed out, videos made by the Center for Medical Progress that were supposed to be only viewed by members of Congress were leaked. Democrats noted that the multiple abortion clinics have been firebombed since the sting videos were released. They also raised the spectre of someone like Robert Lewis Dear -- who admitted to killing three people in November at a Planned Parenthood clinic in Colorado Springs, Colorado -- getting ahold of the names of the researchers and doctors and targeting them.

Democrats argued that the Republicans' subpoenas resembled the "witch hunt" of communists undertaken by former Sen. Joe McCarthy (R-Wis.) in the 1950s.

“There is no reason to create such a database, and the Chair’s abuse of her position to compel this information is reminiscent of Senator Joe McCarthy’s abusive tactics,” she said in her opening statement. “It’s maybe even more dangerous because we have seen people murdered, not just losing their jobs,” she told reporters after the hearing.

Schakowsky said that Democrats would “stand behind anyone who wants to resist providing individual names, personally identifiable information, to this committee.” She expressed doubt that Republicans would push the matter too far, since the entire House would have to vote on a motion to find the organizations who received the subpoenas in contempt if they continued to refuse to provide names.

The hearing itself focused on whether it is necessary for researchers to procure fetal tissue from abortions. Republicans and their witnesses suggested such donations are immoral and coerced, while Democrats defended the practice and noted the various therapies and vaccines that were invented with the help of such research.

Blackburn said the committee’s next steps are to invite more scientists to testify -- which the Democrats said they’d welcome since scientists tend to be on their side -- look at “trends in cellular research” and investigate fetal tissue procurement organizations.