I don't think if Republican voters send RM to the Senate it will be to express their contempt for the institution. That would be the case if they saw him as manifestly unfit to serve as a senator, in the same way that a horse might be. No, if they send him there it will be for other reasons: to help consolidate conservative control of congress and, more generally, support all aspects of the conservative agenda as it impacts many behavioral norms and choices. That they may be willing to do this even if means being represented by a pedophile evidences the strength of their deeply held convictions, be they right or wrong. If they are right, it is surely a case of the end justifying the means i.e. a pedophile is better than an honourable Democrat (assuming that such a thing exists). If they are wrong, they are just a collection of backward people, hypocrites and/or moral embeciles.
The classical reference is however instructive in another way IMO. There have been three Romes i.e. acknowledged preeminent global superpowers: the original of course, the British Empire (on which at its height the Sun never set) and the post WWII American Empire/Hegemony.
As products of human endeavor empires are organic in nature and therefore susceptible to decay and destruction. Sometimes they rot from within, sometimes they are overtaken by competing and hostile forces, and sometimes both things happen at once. At least that is what happened to the Romans and the Brits. Why should America be different? When I look at Trump, an incompetent and clownish bafoon, I see a big step down from even his more modestly accomplished predecessors, let alone the Lincolns and the FDRs. Similarly, the Julian line produced not only Julius and Augustus but also Caligula, the guy who appointed his horse to the Roman senate, and the greatest Antonine, Marcus Aurelius, was succeeded by his son Commodus, who actually fancied himself a gladiator instead of a head of state.
The historian Gibbon blames Christianity for the fall of Rome. I think that the real problem, as is so often the case, was the lack of a succession planning mechanism designed to ensure that the most qualified candidate (or at least a good one) got the top job. I'm sure that there were plenty of Romans hanging around who were more qualified than Heliogabulus. The question with respect to America is whether a carefully crafted Constitution and frequent plebiscites are sufficient safeguards against the election to the highest office of a patently unworthy person and against the damage that he or she might do. While the American system is clearly much better and more efficient than that of Imperial Rome or Ottoman Turkey, it looks to me that it is not foolproof either.