Seventy-two House lawmakers Wednesday sent letters to ABC, NBC, and CBS to express “how profoundly appalled” they are that the networks have “largely ignored” the gruesome trial of disgraced abortionist Kermit Gosnell, as well as Planned Parenthood’s apparent support of infanticide in testimony before the Florida legislature late last month.

“The broadcasters’ blackout of the Planned Parenthood infanticide lobbying scandal and the Gosnell ‘House of Horrors’ murder trial are the biggest and most politically-motivated media cover-ups in our nation’s history,” Tennessee Republican Rep. Marsha Blackburn said. “Censorship and media bias allows the corrupt abortion industry to profit at the expense of innocent women and children. The mainstream media has a responsibility to report the truth, not turn a blind eye to the biggest civil rights issue of our time.”

Late last month, a Planned Parenthood lobbyist told the Florida state legislature that if a baby is born alive as the result of a botched abortion, whether the child lives should be up to the mother, family and doctor.

“We believe that any decision that’s made should be left up to the woman, her family and the physician,” the lobbyist, Alisa LaPolt Snow, told legislators.

Philadelphia abortionist Gosnell is currently in his fifth week of trial for allegedly killing seven babies and one adult woman. (RELATED: Read the graphic details of Gosnell’s alleged crimes)

In their letter, the House members say that the Gosnell and the Planned Parenthood lobbying story “surely … meet your threshold criteria for a national news segment.”

“Yet, despite this obvious fact, coverage of these stories has eluded your news divisions. Our modern world offers no shortage of calamities and crimes to occupy the time of writers, video editors, and announces. Nonetheless, we see no excuse for your failure to report these stories other than blatant media bias,” they wrote, adding that the networks have “betrayed” their viewers and undermined their “credibility in the public square.”

The congressmen added that they would “welcome a response” and explanation as to why these stories do “not merit airtime on your programming.”

“Health care and the protection of the weakest members of society are subjects of high priority for any civilized society. As Americans assess these cases, the condition of our culture, and the utility of our laws, they depend on you,” the letter continued.

“Additionally public officials and lawmakers rely upon an unprejudiced press to follow the truth and report the news, good and bad, for all to see and evaluate appropriately. For these reasons, we urge you and your colleagues to take seriously our concerns.”

CBS has covered the Gosnell trial with online stories and televised reports in recent days. NBC and ABC have featured some stories about the trial on their respective websites, and on Wednesday morning NBC aired portions of Savannah Guthrie’s interview with President Barack Obama, which briefly touched on Gosnell’s case.

Illinois Rep. Daniel Lipinski was the lone Democrat to sign the letters sent to the three networks.

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