You do realize that prior to the XVII Amendment, there were states that permitted the population at large to choose the Senators? Ultimately though, at the end of the day the XVII Amendment IS AN AMENDMENT. Even if this 'republican' meme that you're stressing here were true, its not, the XVII Amendment CHANGES that....
your are correct, starting about the mid 1870's, states started to directly elect senators and it was unconstitutional, because the constitution spells out how senators are chosen, which is what the states of the compact agreed to when they ratified the constitution.
the issue was a referendum [Oregon system], however under republican forms of government, that is
illegal, .............referendums are
direct democracy.
according to "view of the constitution" printed in 1829, by Washington's AG for the state of PA, all states must be a republican form, if the people alter or abolish their republican form, they can no longer be a state in the union, and must..................leave said union.
however no state was forced out by changing its form, as it should have been done,........ referendums again are direct democracy, and the founders hated both of them.
a republican form, is mixed government [ federalist 40] meaning how government is structured, for our government officials to be elected.......this keeps direct power divided, and not concentrated only in 1 set of hands, which will lead to tyranny.
by the 17th, it changed our form of government to a more democratic form of government, which they founders did not want, and allowed government to expand and usurp state powers.
William Rawle, A View of the Constitution of the United States 295--304, 305--7 1829 (2d ed.)
The Union is an association of the people of republics; its preservation is calculated to depend on the preservation of those republics. The people of each pledge themselves to preserve that form of government in all. Thus each becomes responsible to the rest, that no other form of government shall prevail in it, and all are bound to preserve it in every one.
But the mere compact, without the power to enforce it, would be of little value. Now this power can be no where so properly lodged, as in the Union itself. Hence, the term guarantee, indicates that the United States are authorized to oppose, and if possible, prevent every state in the Union from relinquishing the republican form of government, and as auxiliary means, they are expressly authorized and required to employ their force on the application of the constituted authorities of each state, "to repress domestic violence." If a faction should attempt to subvert the government of a state for the purpose of destroying its republican form, the paternal power of the Union could thus be called forth to subdue it.
Yet it is not to be understood, that its interposition would be justifiable, if the people of a state should determine to retire from the Union, whether they adopted another or retained the same form of government, or if they should, with the express intention of seceding, expunge the representative system from their code, and thereby incapacitate themselves from concurring according to the mode now prescribed, in the choice of certain public officers of the United States.
The principle of representation, although certainly the wisest and best, is not essential to the being of a republic, but to continue a member of the Union, it must be preserved, and therefore the guarantee must be so construed. It depends on the state itself to retain or abolish the principle of representation, because it depends on itself whether it will continue a member of the Union. To deny this right would be inconsistent with the principle on which all our political systems are founded, which is, that the people have in all cases, a right to determine how they will be governed.
