Electors are nominated by state political parties in the months before Election Day, not by voters directly. The specific method varies by state:[2]

Electors are typically loyal, high-profile party members — sometimes even sitting governors or other senior state officials. Federal officeholders (members of Congress, cabinet officials) are constitutionally barred from serving as electors, but state officials face no such restriction. The key criterion is demonstrated loyalty to the party and its candidate.[2]

Faithless Electors