Promoting and excluding are two different things. One religion (Christianity in this case, especially since it is the principle religion of this country and the founders were mostly at least nominal Christians) can be promoted - or helped - without necessarily prohibiting other religions. If that happens, Hindus will be some of the first to be discriminated against, since unfortunately so many people who consider themselves Christians do not have the charitable or broadminded views I ascribe to.
At this point, I am a lot more concerned about bias against religion in general, using the false "seperation" argument than I am about Christianity becoming a state mandated religion.
Ah, there it is. You're blinded by the "jurisprudence" on this issue. Tell me, if Dred Scot was still in vogue today - if the jurisprudence still upheld the Dred Scot decision - would you be here arguing that slaves are just property. No, instead you would recognize that the decisions on the issue from Dred Scot up until today were WRONG. Just as we are arguing that the distorted interpretations of the establishment clause and the ensuing decisions and enforcements are WRONG.
Just because the Supreme Court was established by the Constitution does not make them the final arbiter of whether the contract (the Constitution) is being breached or not. The contract was between the several States and the new Federal (not National - I really hope you will learn the difference) Government. The States are still sovereign and still have a say in the matter.
Your model would be like a group of companies contracting with a builder to build a skyscraper for them and then letting ONLY the builder's legal department be the final arbiter of whether the builder is meeting the contract or not. The companies would have no say when the builder uses the contract to continue collecting money from the companies and to start building all kinds of stuff in addition to the teetering skyscraper because the legal department keeps declaring the alterations and additional projects to be within the contract.