[stylin19a]

Article II, Sec 1, Par 2 of the Constitution explicitly vests the power to choose a slate of electors to the State Legislature.

kind of ? Depends on what "...in such Manner as the Legislature thereof may direct... means.

Over time, state legislatures stopped picking the electors. They get picked by others and we now vote for them.
Interesting article here: https://electoralvotemap.com/how-are-electors-chosen/

Wasn't the PA legislature recently discussing clawing back that responsibility in some form?

Interesting here re: court cases: https://americanmind.org/memo/the-constitutional-authority-of-state-legislatures-to-choose-electors/

The Supreme Court has described the constitutional authority of the state legislatures to determine the manner of choosing electors as “plenary.” See McPherson v. Blacker, 146 U.S. 1, 35 (1892);

and

see also Bush v. Gore, 531 U.S. at 104. It has even noted that, “whatever provisions may be made by statute, or by the state constitution, to choose electors by the people, there is no doubt of the right of the legislature to resume the power at any time.”

This is all starting to make my head go "splurt".

[boxlunch]

So not only were State legislatures originally supposed to vote on the Senators from a state, but they were also supposed to basically be the electors for the presidential election? I didnt know that.