The reason it seems so silly is that I can't really figure out, other than some bishops, who really has an issue with this. Numerous Catholic universities and hospitals have been including contraceptives in their health plans for years. Something like 98% of sexually active Americans use some form of contraception, suggesting that most American Catholics also ignore church doctrine on the matter. Most of them seem to have no issue with the law/order in question. The point is simple: why should the religious bent of an employer be allowed to determine the health choices of its employees? Granted, I don't know why someone who wasn't Catholic would work for them, but obviously it does happen. This isn't an individual freedom issue as far as I can tell, unless you really, really stretch it. And that seems to be how most Americans are looking at it, no matter how desperately the GOP is trying to reframe it.
Obama forcing people to pay for religious schools and hospitals would be rather simply dealt with by the Establishment Clause of Constitution of the United States of America. Google it if you're not familiar with it.
What I find particularly rich, especially for the vehemently antichoice conservative set in the US, is that improving access to contraception would actually reduce demand for abortion, whereas making it harder to obtain such services and products increases the demand. So I'm finding it hard to see where they're coming from, and it seems to be more about control of women than anything else. That's nothing new, though.
My brilliant, much more polemic friend Ian Boudreau offers some better ones, first some humourous ones.
Employers shouldn't be required to violate their religious beliefs by providing coverage for contraception, or serving black people.
Employers shouldn't be required to violate their religious beliefs by being forced to allow menstruating women in their places of business.
You must respect the religious beliefs of your employer, whatever those might be. This may involve wearing a special hat.
Employers shouldn't have to violate their religious beliefs by being forced to pay employees who might use their wages for alcohol or ham.
He actually goes into the whole thing a lot more deeply here: http://www.angryblacklady.com/2012/02/05/more-thoughts-on-catholicism-and-contraception/#more-67359 - specifically tackling the special pleading that it takes to actually make an issue of this. It's well written (as is most of his stuff) and worth the time.