In a depressingly familiar display of irresponsible politicking, the US House of Representatives has taken aim at three studies funded by the National Institutes of Health (NIH). Representative Darrell Issa (Republican, California) introduced an amendment killing the projects on 24 July, during a debate on the NIH's 2010 budget. The House passed the amendment by a voice vote.

Issa was unhappy that the studies looked at substance abuse and HIV risk behaviour, and that the subjects were outside the United States. One focused on Russian alcoholics, another on female sex workers in China and a third on female and transgender prostitutes in Thailand. All three passed muster with NIH peer reviewers, and together would cost about $5 million over five years. Issa wanted that money to be spent at home, and complained that HIV had been heavily studied already. But his reasoning is specious: alcoholism, prostitution and HIV do not respect borders, and any behavioural information that could help slow the transmission of HIV is crucial. Some 33 million people are infected worldwide, and a vaccine is nowhere in sight.

Issa's tactic is not new. Since 2003, conservative House Republicans have tried at least five times to strip funding from peer-reviewed projects that drew their ire. Such meddling threatens to undermine the peer-review process as well as potentially eroding the public's trust that science is above politics.

Also worrying is the House Democrats' acquiescence to Issa's amendment. Democrats facing tough re-election bids hoped to dodge Republican attacks in media adverts in their home districts that might have resulted from opposing Issa. Their assumption is that the amendment can be quietly removed when House and Senate negotiators meet to square their versions of the NIH bill before a final vote on it. But Congress should renounce all tactics that undermine peer review — and cease indulging those who use them.