The All-Encompassing Equal Protection Clause

One of my grandfather's books, Structure and Relationship in Constitutional Law (which I recently read for the first time), consists in large part of the exercise of arguing that most or all of the content of the Due Process and Equal Protection Clauses (and perhaps Privileges and Immunities, too, if it weren't so diminished by case-law) would be contained in the Constitution even if those Clauses had never been written into it. Likewise he argues that the First Amendment freedom-of-speech right, at least as applies to its 'core' of political speech rights, would be properly read into the Constitution even if the words specifically granting the right were lacking. He uses his "structural" reasoning form, in essence arguing that the structure our Constitution establishes, that of a federal republic, and the relationship of citizen contained in the first clause of the Fourteenth Amendment require, between the two of them, rights to political (and quasi-political) speech, due process of law, and equal protection of the laws.

It's a very interesting line of argument, and I think I basically agree with him about it, but whereas he wanted to take away the Equal Protection Clause and then reconstruct it from structure and relationship, I find myself drawn to seeing how much of the rest of the Constitution we can strip away and then reconstruct purely from the Equal Protection Clause. (All of this is on the assumption that we have good reasons to incorporate the Equal Protection Clause against the federal government as well as the states, which (under Bolling v. Sharpe) we do.) I think it's obvious that the Fifteenth and Nineteenth Amendments can be properly read into the Equal Protection Clause, and (in combination at least with the citizenship and Privileges and Immunities Clauses) so can the Thirteenth. More ambitiously, I think a lot of the First Amendment can be properly derived from Equal Protection. Certainly the Establishment Clause, which is construed as prohibiting any kind of second-class citizenship, or even 1A-level citizenship, constructed on the basis of religion. Equal Protection prohibits second-class citizenship on the basis of anything. If I were in a more ambitious mood or it weren't late at night (and me with seventy pages of reading to go before I sleep!), I might try to construct arguments for inferring the Free Exercise Clause or the protections of speech, the press, assembly, and petition from Equal Protection, although as Grandfather noted the latter protections can be largely derived just from the words "democracy" and "citizenship."

Since it comes after the First Amendment, I also think it's reasonable to view the Equal Protection Clause as modifying to a certain extent the content or structure of the rights in the First Amendment. In particular I think the Equal Protection Clause has interesting ramifications for the Free Exercise Clause, in that I'm pretty sure under Equal Protection if not under the Establishment Clause, as Scalia claims, government shouldn't get to discriminate against the class of non-religious persons. That statement has some import in considering the question of whether to grant religious exemptions to facially-neutral laws of general applicability: mustn't we also grant exceptions for secular conscience? And, if so, what is left of law? Cannot the pothead claim that his conscience demands that he smoke marijuana? And if not, how can we reject this claim, while accepting the claim by certain persons that their religion requires that they smoke peyote, and not in essence give a lesser set of rights to the non-religious?