One correction: Colorado currently uses semi-open primaries in which independents are allowed to vote in the primary of their choice (but Democrats can't vote in the Republican primary and vice versa). Even this is problematic, however. As you note, "an independent voter registered as a Democrat in a lopsided GOP district or state, or as a Republican in heavily Democratic districts and states, that voter would still have no say in who gets elected." This isn't just a matter of registration; if the voter prefers the Democratic candidates in a GOP-favored district, even in Colorado's system, this voter has to vote strategically in order to have a meaningful voice.
Interestingly, Top-4 RCV often fails to address this issue because RCV functions similarly to partisan primaries in districts that aren't extremely lopsided (e.g. 75%-25%). If a district is 60% Republican and 40% Democratic, and voters behave honestly and in line with their partisan preferences, a Democrat and a Republican will make it to the final round, and whichever Republican makes it there will win the election. Is the same situation you get with partisan primaries: voters who rank all the Democrats above all the Republicans get no say in which Republican gets elected. In more competitive districts voters have to worry about electability for the same reason they have to worry about it in primaries; a failure to consider electability caused Republicans to lose the 2022 Alaska special House election since they would have won the seat if enough of them had strategically ranked Begich over Palin.
Top 4 is only a slight improvemnet so long as RCV is NOT used in the priimary. I know you think that it allows minor parties and independents to get in the general election when the majpor parties split teir vote but that ain't gonna happen. The only time a minor part candidate is likely to make the general under this system is when one major marty is so entrenched that the other party doesn't run anyone. We should get rid of government primaries, create reasonable rules for anyone to get on the general election ballot regardless of party affiliation (or not), allow parties to endorse by their own rules and at their own expense, allow candidates to show any party endorsements on the generl ballot, and run that election by RCV.
Top Four is two bad ideas rolled into one, keeping the worst parts of both.
It starts with a "primary" held using FPTP (the system we're all trying to move beyond), which suffers heavily from vote-splitting and can eliminate the most-representative candidates prematurely. It encourages many candidates to run, acting as spoilers, and gives the false impression that it's OK to vote honestly, amplifying vote-splitting so much that the top four are essentially selected at random.
Then it follows with an RCV general election (Hare's Method, specifically), which is marginally better than FPTP but still fundamentally based on the same flaw of looking only at first-choice rankings. So first-choice rankings get split between similar candidates, and each round of RCV can also prematurely eliminate the most-representative candidates.
The overall concept of "Open primary + Top 4 general" is great, but the two voting methods that are always used in practice are obsolete junk, and the people promoting them don't understand what they're doing.
One correction: Colorado currently uses semi-open primaries in which independents are allowed to vote in the primary of their choice (but Democrats can't vote in the Republican primary and vice versa). Even this is problematic, however. As you note, "an independent voter registered as a Democrat in a lopsided GOP district or state, or as a Republican in heavily Democratic districts and states, that voter would still have no say in who gets elected." This isn't just a matter of registration; if the voter prefers the Democratic candidates in a GOP-favored district, even in Colorado's system, this voter has to vote strategically in order to have a meaningful voice.
Interestingly, Top-4 RCV often fails to address this issue because RCV functions similarly to partisan primaries in districts that aren't extremely lopsided (e.g. 75%-25%). If a district is 60% Republican and 40% Democratic, and voters behave honestly and in line with their partisan preferences, a Democrat and a Republican will make it to the final round, and whichever Republican makes it there will win the election. Is the same situation you get with partisan primaries: voters who rank all the Democrats above all the Republicans get no say in which Republican gets elected. In more competitive districts voters have to worry about electability for the same reason they have to worry about it in primaries; a failure to consider electability caused Republicans to lose the 2022 Alaska special House election since they would have won the seat if enough of them had strategically ranked Begich over Palin.
Top 4 is only a slight improvemnet so long as RCV is NOT used in the priimary. I know you think that it allows minor parties and independents to get in the general election when the majpor parties split teir vote but that ain't gonna happen. The only time a minor part candidate is likely to make the general under this system is when one major marty is so entrenched that the other party doesn't run anyone. We should get rid of government primaries, create reasonable rules for anyone to get on the general election ballot regardless of party affiliation (or not), allow parties to endorse by their own rules and at their own expense, allow candidates to show any party endorsements on the generl ballot, and run that election by RCV.
Top Four is two bad ideas rolled into one, keeping the worst parts of both.
It starts with a "primary" held using FPTP (the system we're all trying to move beyond), which suffers heavily from vote-splitting and can eliminate the most-representative candidates prematurely. It encourages many candidates to run, acting as spoilers, and gives the false impression that it's OK to vote honestly, amplifying vote-splitting so much that the top four are essentially selected at random.
Then it follows with an RCV general election (Hare's Method, specifically), which is marginally better than FPTP but still fundamentally based on the same flaw of looking only at first-choice rankings. So first-choice rankings get split between similar candidates, and each round of RCV can also prematurely eliminate the most-representative candidates.
The overall concept of "Open primary + Top 4 general" is great, but the two voting methods that are always used in practice are obsolete junk, and the people promoting them don't understand what they're doing.