[Repealthe17thAmendment]

Moreover, Gellman acknowledged that the alleged Republican effort is entirely constitutional. Article II, Section 1 of the U.S. Constitution says: “Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress.”

While this is true, it's likely that each state also has a law which determines how those electors are chosen, and it's almost certainly based on the popular vote.

Still, I think it's a good strategy to keep the pressure on the Democrats, and let them know that any vote counting irregularities are going to be closely scrutinized.

[Meatspace]

“While this is true, it’s likely that each state also has a law which determines how those electors are chosen, and it’s almost certainly based on the popular vote.”

Each of those Republican legislatures can vote to change the law and direct their Electors to vote for Trump.

[joshua c]

A law the legislature can change

[Petrosius]

While this is true, it's likely that each state also has a law which determines how those electors are chosen, and it's almost certainly based on the popular vote.

Most likely true but the Constitution gives the authority exclusively to the state legislatures, not to state legislation which needs the approval of the governor. The various legislatures are free to do whatever they want, the objections of the governor notwithstanding.