What is meant by the provision about electors in the Seventeenth Amendment?

Question

I was reading about the Seventeenth Amendment and had a question about one of the sentences in its opening paragraph:

The Senate of the United States shall be composed of two Senators from each State, elected by the people thereof, for six years; and each Senator shall have one vote. The electors in each State shall have the qualifications requisite for electors of the most numerous branch of the State legislatures.

What does this phrase mean? Is this referring to Electoral College electors? To the voters in the state casting votes? To the officials up for election? I've done some searching online about this and haven't really found anything on the subject.

Answer 1

It refers to the voters in the state who cast votes. "Elector" isn't a special term invented for the Electoral College, it just means "person who votes in the election." For President, the real election is technically when the Electoral College votes, so those are the "electors." For Senate, the real election is when the people of the state vote, and so every qualified voter in the state is an elector. The provision means that a state has to set the same standards to vote for Senate as to vote for its own legislature; this has always been true for the House, and limits the extent to which a state can undermine the concept of popular election of Congress.

Answer 2

There are or have been numerous rules about who can vote, for example women could not vote in many states when the 17th Amendment was ratified, and could only vote in school elections in some states. The federal government generally does not say who gets to vote (although there are amendments that prohibit using sex, race etc.), so setting elector qualifications is left up to the state. This clause answers the question, who gets to vote for US Senators? It does not refer to Electoral College electors (indeed, presidential electors cannot be US representatives, senators or "hold an Office of Trust or Profit under the United States", but such government officials can vote for US Senator). "Elector" simply means "gets to elect", and the quirk is that it's actually the members of the Electoral College who elect the president.