The problem with the whole "religious liberty" argument is rather simple: One chooses to act within their own belief system, what about their rights to act within theirs....So thusly if someone who believes abortion is okay wishes to promote it because it's their religious belief, they'd be free to do so. In other words, one is imposing on their rights just as much as they are on ours...or something to that degree.
Now that brings us to three questions that we need to answer:
1) Do we have a right to someone else's skills or labour?
2) At what point is it okay to use discrimination?
3) What role, if any, should the government play in this?
a. I would say to the first that we do NOT have a right to someone else's skills or labor. (The obligation to help neighbour is an entirely different point). We can't demand charity, or demand a particular good or service. I could ask for a piece of marble cake, but no one is under an obligation to give me (or sell me) a piece of marble cake (now one might argue it's a good idea to get me the cake, but that's another discussion)...Reason being? What if you're unable to fill the task? I can't ask for the impossible. If one doesn't know how to bake a cake, how can I ask for it....Of course one might say my analogy isn't perfect because in these situations, it's clear they can...
b. A society that doesn't discriminate to varying degrees would fall apart....Do we not put criminals in jail? This is a form of discrimination (in the positive sense). I think since we've been bombarded with discrimination in the negative sense, we tend to forget it can be used in a positive way as well. Do we not choose freely who we associate with? One can't force someone to speak to someone they don't wish to speak to. Yes, this is a double edged sword, but I'd argue instead of whining to the government, waaa, waaa, waaa every single time people choose not to associate with one another, perhaps one should go search the lands for someone who will associate with whoever it may be...(or in this case sell goods)...(the only time the government actually does need to perhaps step in is when there's no opportunity for business anywhere)
It's relatively obvious that the uproar is more about power, than it actually is about discrimination. There are a number of places that will bake cakes, do "gay marriages" and people that wish for these things can very easily find these people (there's this thing called the internet)....
With ownership does come a responsibility to exercise some type of discretion (discrimination) for particular things. You would not sell a gun to someone who threatens to kill people. A cake is not a right, one can get a cake from anywhere.
c. The (federal) government shall not pass a law prohibiting the free exercise of religion....I can agree that individuals that are religious own businesses. Religion is of course both a private and public act. And the government should protect this (with due limits).
A last point on this rant, one does not have a right to be protected from a jerk. One has a right to self defense, but if people so choose to act with their wills as jerks, they can't be forced with the law to act opposite of this.
As a society, I tend to think that we look to others to solve problems which should be solved at the local level. The Church in her infinite wisdom has given us the principle of subsidiarity, perhaps it should be looked at.