Maine voters passed it via ballot measure, no partisan politicking required. Likewise, the two states voting on it this year, Alaska and Massachusetts, are also doing so via ballot measure.
> The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing Senators.
There have been two Supreme Court decisions that have analogized the electorate as a legislative body in ballot measures, referendums, public initiatives, etc. The latest was https://en.wikipedia.org/wiki/Arizona_State_Legislature_v._A... [1] In that decision it was the liberals and Kennedy who upheld precedent; all the conservatives would have prohibited direct public votes on Congressional election rules. But now Kennedy and Ginsburg are gone, and their replacements are very likely to vote against precedent if the question comes back to the court. (In fact, IIRC, some justices, like Thomas, don't even like the idea of public initiatives for purely state elections, an argument based on their own peculiar notions of Federalism. Also, if you read the order opinions over the last few weeks by Kavanaugh and Gorsuch, some of their arguments seem to be aimed at reversing Arizona.) Roberts might switch his vote to uphold precedent, but Roberts would only make 4 votes, not enough to save it.
If (or, rather, when) SCOTUS prohibits the public from directly legislating their Congressional elections, only Congress could restore the ability, unless the Constitution was amended.
[1] Skimming through the Arizona case, I think the first was Pacific States Telephone & Telegraph Co. v. Oregon, 223 U. S. 118 (1912). But I don't have time to reread the Arizona opinions carefully to refresh my memory.
> Maine voters passed [ranked-choice voting] via ballot measure, no partisan politicking required. Likewise, the two states voting on it this year, Alaska and Massachusetts, are also doing so via ballot measure.
My point is that for Federal congressional elections the legal capacity to use voter initiatives to institute different voting rules, bypassing partisan state legislatures and Congress, will likely be extinguished in the coming years. The same is likely true for Presidential elections as the relevant constitutional language is nearly identical: "Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors...."
My comment about Thomas' view (uncited--I could be misremembering the nuances) about who gets to pass laws controlling state legislature elections was merely to suggest how likely he would be to overturn Arizona; his opinion about the Constitution's and SCOTUS' role in dictating/safeguarding a very specific form of representative government extends beyond a simplistic plain text[1] interpretation of the aforementioned constitutional clauses.
[1] I feel like I should point out that no justice, conservative or otherwise, subscribes to a "plain text" philosophy of constitutional interpretation. Conservatives justices tend to espouse either a so-called Original Intent philosophy or Scalia's Original Meaning philosophy, where "Original Meaning" is not the same thing as "plain text". And justices of all political philosophies will make a "plain text" argument when it suits their interpretation. All things being equal (though they rarely are), everybody tends to agree a plain text defense is the best defense.
The most recent U.S. Supreme Court nominee briefly talks about some of the nuances related to precedent here: https://www.youtube.com/watch?v=nlchBfW036s
The (old) British legal scholar William Blackstone dives into it in his work "Commentaries of the Laws of England" (Introduction - Section 3) if you want a more thorough understanding of the foundation of precedent in common law.
TLDR and very over-simplified:
Legal precedent is established until the laws change. The various legislatures/governing-bodies of the US can change the law whenever they please. When those laws then come into conflict with other laws out there, you have to have a ruling by a court. Sometimes this is intentional.
Which court does the ruling is super complex and sometimes they are not called courts, FYI. Judicial bodies, sometimes called courts, are also super complex. In general, the US legal system is more like the Ancien Régime than anything else, in that we strive to make sure no two people are governed under the same law. Just kidding, sorta. ;)
In the case of SCOTUS, they mostly rule on matters that affect the US constitution, and only if they feel doing so. They then make a ruling, and that becomes the new way the laws work. Sometimes this makes a law null-and-void, sometimes it just sets guidelines on how to make a law function. Again, super complex. There are many other courts in the US that can similarly do things at laws, but SCOTUS gets the most news.
That said, I wouldn’t support it. I view State-level ballot initiatives as an anti-feature, at least in my native California. Wouldn’t want that crap making it up to the Federal level.