That's why I say that the idea that Congress can thwart a convention of states by holding some sort of implied "same-subject" requirement over the states is just another surrender of power - this time it's the states' power to compel a proposing convention.
The 17th amendment changed the nature of Congress, but it didn't change the plain language of Article V, calling a Convention for proposing Amendments - plural.
Demanding a same-subject requirement just hands Congress a weapon to use against the states to prevent them from organizing, when no such requirement seems to exist in the Constitution or in the Federalist Papers writings.
-PJ
But absent the controlling link to the state legislatures, what powers does the Senate legitimately exercise under the Constitution? The Seventeenth Amendment absolutely extinguished the entire raison d'être for the Senate as envisioned by the Framers of the Constitution that the Senate is the representative body of the States in Congress.
And it's all been downhill from there.... Now it seems that the only people Senators "represent" is themselves.