WASHINGTON, DC - JULY 28: Anti-abortion activists hold a rally opposing federal funding for Planned Parenthood in front of the U.S. Capitol on July 28, 2015 in Washington, DC. Sen. Rand Paul (R-KY) announced a Senate deal to vote on legislation to defund Planned Parenthood before the Senate goes into recess in August. (Photo by Olivier Douliery/Getty Images)

The surprise of today's Republican press conference on Planned Parenthood came when one of the freshman class's stars praised Hillary Clinton. Sen. Joni Ernst (R-Iowa.) described how undercover videos had found the family planning group's executives coldly discussing the sale of fetal body parts, and said that even Democrats were recoiling.

"The American people, Republicans and Democrats alike, are horrified by the utter lack of compassion showed by Planned Parenthood for these women and their babies," said Ernst. "In fact, now, Hillary Clinton is calling these Planned Parenthood images disturbing, and I agree.”

That line had the intended effect. It rattled abortion rights supporters, reminding them that the Democratic frontrunner for president had hedged on their issue. The fight to defund Planned Parenthood is only the latest in a series of conservative attempts to shift the conversation on abortion, from one that bedevils Republicans to one that flummoxes Democrats. Instead of speaking generically -- and popularly -- about "women's health care," the Planned Parenthood sting forced Democrats to confront the little-covered and gruesome issue of fetal tissue sales.

Clinton's "disturbing" comment, made in an interview with New Hampshire's Union Leader, landed poorly. It did not matter that Planned Parenthood's CEO Cecile Richards had apologized for the conversations in the video sting. The Democratic frontrunner, seemingly, had been forced into a defensive crouch. "She needs to clarify what her [point of view] is, and articulate it strongly and without apology," former Planned Parenthood president Gloria Feldt told MSNBC's Irin Carmon. "I just think that when candidates get to the firing line of a campaign they get thrown off balance and waffle."

Clinton's closest competitor, Vermont Sen. Bernie Sanders (I-Vt.), fared no better -- at first. On July 17, when the videos broke, he cited Richards's statement and averred that "the tone was terribly wrong" in the fetal tissue conversation. "He has not gone out of his way to defend the group," wrote Mother Jones reporter Molly Redden in an article shared nearly 3000 times on Facebook.

Only today -- before the Senate GOP press conference -- did Sanders release a new statement about the coming vote to defund Planned Parenthood. "The current attempt to discredit Planned Parenthood is part of a long-term smear campaign by people who want to deny women in this country the right to control their own bodies," said Sanders. "Let’s be clear: Federal funding for Planned Parenthood does not pay for abortions. The vast majority of government funding that Planned Parenthood receives is through Medicaid reimbursements."

That looked like a move to Clinton's left -- but for some, it was too clever by half.

"It's a little mealy-mouthed, no?'" said the feminist columnist Katha Pollitt. "As I read it, he doesn't defend abortion specifically. He says Planned Parenthood provides gyno care for millions of poor women."

Conservative news sites, spotting an opportunity, have repeatedly asked the Democratic presidential candidates to talk about the videos. None have been willing to defend the videos' contents.

"I haven't seen the videos. And I don't generally make a habit of responding to right-wing videos," O'Malley told reporters in New Hampshire this week. "I do know that 97 percent of the work that Planned Parenthood does is about mammograms and preventative health. So that's what I know but I'll defer to others for commenting on that video and whatever videos they're pumping out there."

Update: In 2012, the Washington Post's Josh Hicks fact-checked claims about Planned Parenthood and mammograms. The group does not provide them; it does provide referrals and advice on how to pay for them.