A new Republican super PAC is invoking the name of the deceased Supreme Court Justice Ruth Bader Ginsburg in an audacious attempt to defuse the volatile issue of abortion as a liability for Donald J. Trump.

The group, which is called RBG PAC and came into existence only days ago, began to spend $20 million on Friday in support of Mr. Trump, according to federal records. The group posted two abortion-themed ads focused on Mr. Trump’s declaration that he would oppose a federal abortion ban.

The move is a brash one, because Mr. Trump deliberately appointed justices to overturn the federal right to abortion, and Justice Ginsburg openly despised the former president. “He is a faker,” she said during his 2016 run for president. “He has no consistency about him.” On Friday, her family rebuked Mr. Trump’s allies for invoking her name, calling the effort an affront to her legacy.

The group’s paperwork was signed by May Mailman, who worked in the Trump White House and who is now the director of the Independent Women’s Law Center. She did not respond to a request for comment Friday.

Ms. Mailman posted the ads online and said they featured a “suburban mom” who had never voted for Trump before but was backing him now because he has said he opposes a national abortion ban.

The ad she posted features a woman in a pink sweater sitting in a chair in a living room saying her life was better under Mr. Trump. She says that “freedom to choose is also important to me” and that she is voting for Mr. Trump, citing his support for exceptions to abortion restrictions in cases of rape, incest and risk to the life of the mother.