>The U.S. Supreme Court has repeatedly characterized the authority of the state legislatures over the manner of awarding their electoral votes as “plenary” and “exclusive.”<
Do you happen to know which case that was?
The leading case on the awarding of electoral votes is the 1892 case of McPherson v. Blacker. As the U.S. Supreme Court stated in that case:
“The constitution does not provide that the appointment of electors shall be by popular vote, nor that the electors shall be voted for upon a general ticket [the winner-take-all rule] nor that the majority of those who exercise the elective franchise can alone choose the electors. It recognizes that the people act through their representatives in the legislature, and leaves it to the legislature exclusively to define the method of effecting the object. The framers of the constitution employed words in their natural sense; and, where they are plain and clear, resort to collateral aids to interpretation is unnecessary, and cannot be indulged in to narrow or enlarge the text. …
“In short, the appointment and mode of appointment of electors belong exclusively to the states under the constitution of the United States.”
In Bush v. Gore in 2000, the Court approvingly referred to the characterization in McPherson v. Blacker of the state’s power under section 1 of article II of the Constitution.
“The individual citizen has no federal constitutional right to vote for electors for the President of the United States unless and until the state legislature chooses a statewide election as the means to implement its power to appoint members of the Electoral College. U.S. Const., Art. II, §1. This is the source for the statement in McPherson v. Blacker, 146 U.S. 1, 35 (1892), that the State legislature’s power to select the manner for appointing electors is plenary; it may, if it so chooses, select the electors itself, which indeed was the manner used by State legislatures in several States for many years after the Framing of our Constitution.