Seems simple enough. It prevents unwanted pregnancies without functioning as an abortifacent, it costs too much to be popped like TicTacs (which ought to assuage at least some of the concerns of our moral guardians), and it's safe.
So of course, there's a problem.
This is lunacy, pure and simple. This is something that can literally prevent thousands of actual abortions per year, and these people want to throw it out because, well, there are rare exceptions where a fertilized egg -- keeping in mind that this has to be taken within 72 hours of intercourse -- might be prevented from implantation in the uterus. That is not moral purity, that is simply blind, destructive absolutism. It's not "complicated" at all, it's a choice between thousands of abortions per year prevented outright versus the chance of a few dozen newly-fertilized eggs not being implanted.
PZ Myers has what is the best explanation of exactly how Plan B works, and why it has nothing whatsoever to do with the abortion issue. There's also an update on how the media, "objective" as always, have utterly screwed up the factual narrative to the "prevents implantation" caveat, as if it had some actual clinical basis, which it does not. And as Myers points out, even if it could be empirically shown that 1 (or 10, or even 1000) of every million uses resulted in such a prevention of implantation, so what?
The line of what constitutes "protection of life" gets pushed further and further back toward the very moment of ejaculation, practically. That this nonsense continues to be presented seriously and "objectively" is a disservice to the practical ramifications of the argument, which affect a lot of actual -- not merely potential -- lives.
One side actually wants to get the number of abortions as low as possible; the other wants to eviscerate Griswold and establish an unconscionable level of control over womens' (specifically) sex lives. Perhaps this would be less of a "contentious issue" if the media presented it as such, rather than continuing this noxious pretense that if we squint hard enough, maybe 2+2 really does equal five.