TWENTY CLINICS in Virginia performed slightly more than 25,000 first-trimester abortions in 2011. In carrying out that legal, safe and relatively simple procedure, there were very few reports of mishaps or complications. For the most part, patients were in and out of the clinics within two or three hours.

Nonetheless, in that same year Republicans in Richmond enacted legislation requiring stringent and unnecessary rules that would reclassify abortion clinics as the regulatory equivalent of hospitals. The likely effect of those rules, which Gov. Robert F. McDonnell (R) endorsed as quietly as possible last week, will likely be to force the closure of as many as half of the state’s clinics, which account for at least a third of Virginia’s abortions.

That means something on the order of 8,000 to 10,000 women will be unable to find nearby clinics if they want abortions. Their quest will be further complicated by rules requiring 24-hour waiting periods for abortions after initial examinations and newly mandated ultrasound procedures, which in some cases cannot be performed on the same day. Particularly in rural parts of the state, getting an abortion will become extremely difficult, if not impossible.

That, of course, was precisely the intent of Mr. McDonnell, Attorney General Ken Cuccinelli II (R) and their fellow anti-abortion Republicans in the General Assembly. With precious little evidence to justify the tough new regulations on health grounds, they forced them on Virginia women to satisfy an ideological, and in some cases theological, agenda.

For example, the new regulations require that abortion clinics be furnished with ventilation equipment up to the standards of hospital operating rooms, where surgery demands sterile conditions. But unlike most hospital surgeries, abortions do not involve incisions, and there is no evidence that enhanced ventilation in abortion clinics will bring the slightest improvement to patients’ welfare. The only point is to burden clinics with huge costs — ventilation upgrades can cost tens of thousands of dollars or more — in the hope that will force them out of business.

Other such perversities in the new regulations include minimum parking requirements and mandated widths for hallways and doorways. In all, the rules will cost clinics millions of dollars, all brought upon them by Republicans who claim to regard excessive government regulation as anathema.

The new rules prompted the state’s health commissioner, Karen Remley, to resign in October, saying they would make it impossible to fulfill her duties. That should have been a red flag to Mr. McDonnell and the equally zealous Mr. Cuccinelli. But they forged ahead with rules designed to make health care less available for women.

Now, with the governor’s endorsement — delivered on a Friday between Christmas and New Year’s Day, with nary a press release to mark the occasion — the rules will likely be finalized (after another period of public comment) by summer. After that, clinics will have until the second half of next year to comply. When some start shuttering their doors, the abortion issue will have left another blot on Virginia’s name.