"Secession belongs to a different class of remedies. It is to be justified upon the basis that the States are Sovereign. There was a time when none denied it. I hope the time may come again, when a better comprehension of the theory of our Government, and the inalienable rights of the people of the States, will prevent any one from denying that each State is a Sovereign, and thus may reclaim the grants which it has made to any agent whomsoever."
President Jefferson Davis.
And when was that exactly?
In point of actual historical fact, Lincoln did absolutely nothing to alter the relationship of the states to the federal government.
The Confederacy sought to do so, and Lincoln restored the previous, Constitutional order.
The Confederates were the radicals and innovators against the Republic as it was.
As far as the 17th Amendment was concerned, its most forceful advocate was William Jennings Bryan, the Democrat Secretary of State, who spoke frequently in support of the Amendment. It was a coalition of Southern and Western Democrats who got the amendment passed.
The most ardent foe of the 17th Amendment was the Republican Elihu Root - he and a hard core of ten Republican senators opposed it to the end, and they lost their seats in the popular elections that followed.
The Constitution in its very text forbids secession (the Supremacy Clause) and the Framers specifically repudiated this stupid idea in The Federalist.