The song is not all about the anti-abortionists, though the title may have been inspired by the organization.

"Life ever-after is what they're in business for, see them brandish the key to their kingdoms door." This has to do with Heaven and Christianity. not fetus' being used for stem cells. It is basically saying that Man either cannot be saved, or doesn't need to be, anyway. Depending on whether God actually exists. They are either beyond saving for God, OR they just don't need it because there is no God. Either way, to try to rescue us is pointless.

Operation Rescue is a Right wing-anti abortion Christian Extremist group which set up barricades at abortion clinics in the State. Its run by Randall Terry (in the 'Tested' version Greg can be heard snarling 'Randall Terry'.)
I think the songs pretty literal from here although it obviously has wider implications.

Operation Rescue was/is an Antiabortion group that radicalized the pro-life movement of the late '80s and early '90s through mammoth clinic blockades and rhetoric equating abortion with murder and the Holocaust. Randall Terry, who founded Operation rescue in 1987 while working as a used-car salesman in upstate New York, and is credited with originating antiabortion civil disobedience and militancy. The group's protests first came to the country's attention at the 1988 Democratic National Convention in Atlanta and peaked with the 46-day shutdown of Wichita, Kansas, in 1991. Three years later, Operation rescue was in splinters. In a single month, RU-486 was licensed for U.S. production, the Freedom of Access to Clinic Entrances Act was signed into law, and a Houston jury ordered OR members to pay $1 million in punitive damages for a 1992 blockade of a local Planned Parenthood clinic. The Catholic Church also began to grow wary of the sidewalk counseling, surveillance, blockade, and harassment tactics taught at the group's Melbourne, Florida, training center. After Minneapolis was selected by OR in 1993 as one of seven 'cities of refuge,' the archbishop there explicitly asked OR to stay away. The March 1993 murder of Florida doctor David Gunn led to a split between those condoning and condemning the violence--Terry left OR for the militia-affiliated United States Taxpayers Party, while some of the group's most strident leaders formed the American Coalition of Life Activists, a group that in 1995 published a 'Deadly Dozen' list targeting 12 American abortion doctors for harassment. By the mid-'90s, the internally divided OR had lost considerable visibility.

I saw a post that someone had put on this site about the song 'Operation Rescue.' I was rather shocked at their apparent ignorance of what that organization is and what they do. The 'interpretation' was what you could call 'out of left field.' Operation Rescue, as I'm sure most of you know, is an organization that fights for the rights of unborn children. They have saved hundreds of thousands of unborn babies from being aborted. Now, following in Greg Graffin fashion of his very apparent dislike and confusion over organized religion and their 'causes,' you find him questioning their motives and their desire for this fight. The whole song is about why they do what they do. Hence the lyric, 'you wonder where they come from, but I just wonder what compels all.' Greg Graffin has an amazing mind and great lyrics that drive a lot of people to think. I have been a fan for just about the whole time they've been around. Just make sure you don't follow his philosophy just because he is who he is. I'm sure Greg would tell you the same thing. In fact, he has a lyric saying, 'no Bad Religion song can make your life complete. Prepare for rejection, you'll get no direction from me.'

'Operation Rescue' (as seen here: http://www.orn.org/wwworn/index.htm), now known as 'Operation Save America', is a collection of fundamentalist Bible-huggers who would like nothing better than to impose their views on others. These are the types of people who think Jerry Falwell is good guy. The song, as stated above, is a cynical stab at these strange folk. These people have taken it upon themselves to help those who don't need helping, and, of course, they do it in the name of 'god'. I particularly like the line 'if no one believed in fairy tales (i.e. heaven, god, etc) / there's nothing they could do but fail.'