Just because there are Jefferson quotes that reference opposition to religious leaders running the country does not mean that this was his only concern relating to religion and government. There are a multitude of quotes that I can reference if you'd like, but it should be relatively clear from a logical standpoint that the existence of Jefferson's statements about religious leaders does not prove the non-existence of Jefferson's statements on other aspects of government involvement with religion.
In regard to Justice Black being vilified as the "shark jumper," you're ignoring your history again. The first case of which I am aware that incorporated any portion of the Bill of Rights on a state level was in 1897. In 1927, another pre-Black opinion specifically incorporated the first amendment. In 1947, an opinion involving Justice Black specifically incorporated the religious portion of the first amendment on the state level. Although there were four dissenters in that opinion, the court actually unanimously agreed that the religious portion of the first amendment should be incorporated on the state level. The disagreement was regarding whether state governments could reimburse religious schools from tax payer dollars. As much as you vilify Justice Black, you should be made aware that he actually upheld the law due to the reimbursements being given to all schools regardless of religious affiliation or lack thereof.
Who knows what "respecting" meant in 1780 something?
So, let's get this straight. You want to primarily focus on the plain wording of the Constitution, but then you turn around and say that you don't know what a word meant in the 1700's? How are you supposed to tell anyone what the Constitution means when you essentially just admitted to not knowing the definition of a word used in the Constitution? The moving argument strikes again.
The US government can't create a law that relates to establishing a national religion. Bam! It's pretty clear. ESTABLISHING RELIGION means CREATING (or ENDORSING) a government-run church.
The Constitution does not use the verb "establishing," nor does it refer to the government establishing anything. Rather, it says that no law may be passed respecting an
establishment of religion. There is no reference to who established it, or that who established it is even important. Rather, it merely states that no law shall be made respecting an establishment of religion.
In fact, if a law is passed in reference or in regard to an establishment of religion, then this suggests that the establishment already existed in order for the law to reference or be in regard to it. If the amendment was intended to only prevent the government from establishing a U.S. church, then two things would be mentioned.
First, the amendment would mention the fact that the government is prohibited from establishing a U.S. church; there would not be the grammatical implication that the religious institution is already in existence, nor would there be use of the word "respecting" instead of "establishing," "creating," "forming," or something similar to denote that the government is the creator of the establishment.
Second, the amendment would specifically reference that the religious establishment is government controlled/owned/operated, as opposed to the ambiguous wording of "an establishment of religion."
This can be seen by an initial draft of the amendment, which stated, "The civil rights of none shall be abridged on account of religious belief, nor shall any national religion be established . . ." This draft was rejected. Had the establishment of a U.S. church/national religion been the only thing prohibited, then this wording would have survived, as it much more clearly identifies such a specific prohibition.
But the ultimate question here is, "Why?" Let's suppose that the Constitution was only intended to prevent the government from establishing an official religion or a U.S. church. In effect, this would suggest that the government does not have any one specific religion that it would tout, proclaim, or display. So why would the government want or need to have the ability to specifically display the Ten Commandments, a religious set of rules pertaining to only Judeo-Christian religions? Sure, there's a Constitutional right to freely practice whatever religion you want, but that right prevents the government from infringing upon individual freedoms; it does not suggest that the government has the same freedom. And, as mentioned, the government would have no need for that freedom if it is prohibited from having an official or government established religion of its own.