When Virginia Democrats partied at their annual Jefferson Jackson Dinner in Richmond on Feb. 19, Senate Majority Richard L. Saslaw (Fairfax) crowed about the party’s success in killing efforts by the Republican-controlled House of Delegates to push forward conservative legislation such as anti-abortion bills.

“If we were not there, in the [Senate] majority, this state would [be] like a cross between Alabama, Mississippi and Arizona,” Saslaw said.

Just five days later, however, Saslaw failed to live up to his own boast. A major parliamentary bungle by his leadership team and its pro-choice allies handed anti-abortion conservatives their first significant victory in the state since Virginia made fetal homicide a crime in 2004.

As a result, Virginia health authorities will be empowered to impose regulations on clinics that do first-trimester abortions under a new law that in some ways is among the most onerous in the nation.

Democratic legislators and pro-choice activists are already pointing fingers over who’s to blame for the debacle.

Regardless of whose fault it is, the impact on Virginia women wishing to terminate their pregnancies could be severe. Many, or even most, of the state’s 21 abortion providers could be forced to close because it would be so costly to change their facilities to meet the new standard, under which they’re classified for the first time as a kind of hospital.

It’s hard to predict what the full consequences will be. The broadly worded statute gives the state Board of Health a lot of leeway in defining what kind of “hospital” facilities an abortion clinic must provide.

The 15-member board is currently controlled by members appointed by the previous governor, Timothy M. Kaine, a pro-choice Democrat. But Republican Gov. Robert F. McDonnell, who is strongly antiabortion, will have a chance to replace them all by the time his term expires in January 2014.

“The Board of Health could go for zero or for everything they think is necessary to make it safe,” said Victoria Cobb, president of the Family Foundation of Virginia.

For the sake of discussion, let’s assume that the clinics will be forced to meet standards like those required of outpatient surgical centers. That was the benchmark sought in another Republican-backed bill, similar to the one that passed.

By that guideline, abortion rights supporters say, it would cost millions of dollars to renovate the clinics. Hallways would have to be widened so two gurneys could pass through at the same time. The procedure area would have to be at least 250 square feet. The entrance would have to be covered.

Anticipating that such legislation might pass eventually, Planned Parenthood in recent years remodeled four clinics in the state – in Richmond, Charlottesville, Roanoke and Virginia Beach — to fulfill those criteria. But none of the other 17 abortion providers in the state meets the standard, including Washington area clinics in Falls Church, Manassas and Annandale.

It’s clear that the Senate Democratic leadership wasn’t paying attention when it let a seemingly innocent Republican health bill go through. The legislation dealt with regulatory issues in a way that allowed the House to amend it and turn it into an unstoppable bill targeting abortion clinics.

The leadership “should have seen that coming a mile away,” said a Democratic politician who spoke on the condition of anonymity because he didn’t want to publicly criticize the party chiefs. “The bill was a Trojan horse. We’re playing chess down here, and you must constantly be thinking five to six steps ahead of the game.

“It’s not easy when the bills are flying at the end of the session, but you’ve got to stay focused.”

Some Democrats said pro-choice lobbyists also bore responsibility because they’re paid to keep track of such bills. Saslaw’s brief explanation: “They slipped one through.”

If there’s a bright spot for Democrats in all this, it’s that the new law reminds voters that Republicans will push through conservative social legislation when possible, despite trying to emphasize their credentials as pragmatists focused on jobs and other bread-and-butter issues.

When McDonnell won the governorship in 2009, he “was able to present himself as a moderate, charismatic Republican, which he never was. We have all been bamboozled,” complained Wendy Klein, a Richmond doctor, activist and deputy editor of the Journal of Women’s Health.

Democrats hope a backlash against the legislation might galvanize pro-choice voters in the fall elections and help protect the Senate majority. But Klein despaired over the complacency she saw among supporters of abortion rights.

“Definitely, women have gotten to the point where they take these reproductive choices for granted and don’t seem to realize how at risk these choices are,” Klein said.