Asking you to leave yesterday does not create a "now and forever" situation. When you come back the next day, he may not ask you to leave and just call the cops, but when they arive, they will not arrest you for trespass since you were not asked to leave.
Now what they may do, is give you a trespass letter. Essentially legal notice that the owner never wants you to return. Once given that notice, than you could be arrested for coming back, even if not asked to leave at that point.
As another poster pointed out, only the government is precluding from violating constitutional rights. It has no bearing on private business.
The examples given related to race, religion, and gender are not protected by any constitutional issues. They are protected by civil law related to discrimination. Completely apples to oranges comparision. If someone is discriminated against in such case, they can sue the business.
A more accurate example is the raving lunatic and his 1A rights disrupting the store. Yes, he can be asked to leave. A business owner can legitimately ask anyone to leave if they are disrupting the business. While it may be argued that your 2A rights aren't disruptive it comes down to opinion. Without some law protecting your choice to exercise the right, you have no basis for a suit as there are no damages.
It comes down to choice. Our rights are something we can choose to exercise or not. They are not without limit, and that limit is generally when exercising them infringes on others.