EVEN ardent advocates of a woman’s right to an abortion may grow queasy from watching a series of undercover videos of meetings with representatives from Planned Parenthood, a national group that offers reproductive-health services, including abortions. In order to harvest hearts, lungs and “as many intact livers as possible” from aborted fetuses, providers use ultrasound to make sure they do not “crush that part,” explains Deborah Nucatola, a medical director for the group, between sips of wine. Another shows a medical executive named Mary Gatter apparently negotiating the sale of fetal “specimens”. The videos come courtesy of the Centre for Medical Progress, an anti-abortion pressure group. The three released since July 14th have been watched millions of times, and the group promises “thousands of hours” more. It says the videos show that Planned Parenthood is running a “black market for baby parts”, which is illegal. Planned Parenthood denies this claim, and the recordings do not quite prove that the organisation is profiting from these transactions. But abortion providers at their health centres are apparently aware of the value of fetal tissue, which scientists need for a wide array of medical research. And the videos, with their casual talk of “suction” or a “less crunchy technique”, make for powerful propaganda.

Ted Cruz, a senator from Texas, stirred crowds at an anti-abortion rally on Capitol Hill on July 28th with calls for a federal criminal investigation. Rand Paul, a senator from Kentucky, has been keen to perk up his poll numbers by leading a fight to “strip every dollar” of government funding from Planned Parenthood, which counts on federal and state coffers for nearly $530m of its $1.3 billion annual budget. Senate Republicans plan to vote on defunding the organisation before the August recess.

Polls show that pro-life voters are in the minority, but they punch above their weight because they care more about where politicians stand on the issue. Surveys find that most Americans support keeping abortion legal within the first weeks of conception; but this sympathy plummets once the woman enters her second trimester, and nearly disappears when she reaches her third (see chart), by which time ultrasounds offer more detailed pictures of fingers and toes. Campaigners have worked with this discomfort. Twelve states now require abortion providers to proffer details about a fetus’s ability to feel pain; ten mandate an ultrasound (though it is not medically necessary); and 14 have introduced bans on an abortion 20 weeks after conception.

Defunding Planned Parenthood may seem a logical next step. But federal funding for abortion is already banned, except in cases of rape, incest or where a woman’s life is in danger. Moreover, much of Planned Parenthood’s work involves preventing unplanned pregnancies in the first place. Of the 2.7m patients who used one of its clinics in 2013, eight in ten came for contraception. Three-quarters had incomes at or below 150% of the federal poverty level. These demographics matter because abortion trends divide by income: the rate for well-off women has dropped by nearly 30% in 20 years, whereas for poor women it has climbed nearly 20%. This is largely because poor women, with worse schooling and not much access to health care, are five times more likely to become pregnant unexpectedly.

For every public dollar spent on contraception, the government saves $5.68 in Medicaid spending on pregnancies, according to the Guttmacher Institute, a pro-choice NGO. Planned Parenthood reaches over a third of all qualifying patients, making it the biggest provider of these services. In addition, its clinics carried out 500,000 screenings for breast cancer and 4.5m tests for sexually-transmitted diseases in 2013. The number of abortions performed each year in America has fallen by a third since 1990. Without Planned Parenthood it would be far higher.

CORRECTION: An earlier version of this story said that Planned Parenthood's annual budget is $1.3m, rather than $1.3 billion. Sorry.