They have abused Jefferson's letter, that is. They use the phrase, "wall of separation between church and state," not in the way Jefferson obviously meant it since the letter to the Danbury Baptists was genial, not adversarial, to express protection of the church from the state but only the reverse - which could not have been Jefferson's meaning in context.Just as the Devil can quote scripture, any text can be tortured into adverse meaning - and that would include the Declaration. But in general I think the author of the article has a good point, which is amplified by the preamble to the Constitution. Specifically, it is senseless to try to interpret a document without reference to what the author(s) were trying to do.The preamble to the Constitution contains the phrase " . . . secure the blessings of liberty to ourselves and our posterity . . . " And that is what ties the Constitution to the Declaration - the purpose of the documents was the same. That is the "mission statement," the bumper sticker version, of the Constitution. So long as the Constitution be read with the understanding of its purpose foremost in mind, seizure of General Motors and the overthrow of the private contract via health care "reform" can be seen to be antithetical to the Constitution.
The framers were the same people (specifically George Washington and Benjamin Franklin) who promulgated the Declaration - and their perspective and purpose must be considered to be a constant.The author of the article is trying, IMHO, to say pretty much that.
Very much agree, it has been abused. Justices/judges cull the world for documents to help them interpret ... and ignore the actual BEST documents to do the job.