Rep. Vern Buchanan, a Florida Republican, has called himself “pro-life” since he came to Congress a decade ago. This month, he’s proving it.

Buchanan last week announced his support for President Obama’s request for $1.9 billion to fight the Zika virus – a decision he based in part on “new research revealing that Zika eats away at the fetal brain and destroys the ability to think.”

He’s right about that. The mosquito-borne virus is going to cause thousands of babies in this hemisphere to be born with severe birth defects, and Zika is on the cusp of devastating the U.S. citizens of Puerto Rico and of spreading to the southern United States. Untold numbers of the unborn are being irreversibly harmed.

And yet the supposedly pro-life majorities in both chambers of Congress have done nothing with Obama’s request, more than three months after he made it in early February. Republicans demanded that the administration repurpose money that was supposed to have been spent fighting Ebola, and the administration did so even though that virus has resurged in Africa. Now, the congressional delay is hampering our ability to monitor the spread of Zika, to test possible victims and to prepare a vaccine.

In fairness, the congressional lethargy isn’t limited to Zika. The House has been in session only 210 of the 491 days of this Congress, including 36 days on which no legislative business was done, according to House Democrats’ tally. Only 150 bills have been signed into law – a fraction of historical totals – and 25 of those were ceremonial renamings of buildings and roads.

But with Zika, the delay is inevitably going to cause more fetuses to be deformed – and perhaps aborted – and a caucus supposedly devoted to protecting them is silent. There may never be a consensus on abortion, but can lawmakers not agree to fight a virus that destroys the brains of fetuses?

The few Republican officials who have called for action on the Zika funds have close-to-home reasons. Gov. Rick Scott of Florida, where the risk of spread is high, is coming to Washington this week to urge Congress to act. His fellow Floridian, Sen. Marco Rubio, pleaded for action, too. Rep. Jaime Herrera Beutler, R-Wash., has also supported Zika spending; she’s pregnant with her second child.

On Monday, the National Governors Association, whose mostly Republican members will be on the hook when Zika arrives, urged Congress to act, saying “the nation is on the threshold of a public health emergency” and the prospect of “children born with severe, lifelong birth defects.”

But there’s quiet from the anti-abortion lobby. Groups I checked with haven’t taken a position on the Zika response, other than a few that have said laws against abortion should not be loosened in Latin American countries because of the virus.

National Right to Life published an argument in March questioning whether Zika causes birth defects and citing a study that said only 1 percent of babies born to mothers with the infection have the brain condition called microcephaly. “Abortion advocates would have had us believe the risk of microcephaly was much higher,” it said.

But Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, told a Washington Post editorial board meeting Tuesday that “I can almost guarantee you” that the rate of birth defects is higher than 1 percent; another study puts it as high as 29 percent.

Fauci said “it is very likely we’re going to see local outbreaks of Zika in the United States,” and the U.S. territory of Puerto Rico “is on the precipice of a really serious disaster.” Extrapolating from the pattern of the chikungunya virus, spread by the same mosquito, Fauci said that 25 percent of Puerto Rico’s population of 3.55 million can be expected to contract Zika over the next year – including “a lot of pregnant women.”

And Ed McCabe, chief medical officer for the March of Dimes, told me Tuesday that Zika transmitted by local mosquitoes is on the “doorstep” of the mainland, too. “Every day we wait, we’re at greater risk,” he said. “Congress needs to act.”

Will Republican congressional leaders listen? Democrats have proposed replacing the ad hoc responses to outbreaks (Zika, Ebola, pandemic flu) with $5 billion a year for the moribund Public Health Emergency Fund. This won’t happen in the current political environment.

But taking a sensible step to stop Zika’s spread? Let’s hear no more from so-called defenders of the unborn until they’ve done it.

Dana Milbank is a columnist for The Washington Post. He can be contacted at:

dana.milbank@washpost.com