Should Party List allow voters to disapprove a party/candidate, with a 2/3rds majority banning them from the legislature?

The expelled party/candidate could have an option to transfer their votes to some other party/candidate by ranking them before the election.

This seems to fix a major criticism of PR, which is that dangerous extremists can get elected with a tiny sliver of votes.

Also, do most PR legislatures have the power to expel representatives, and if so, have they used it much? There have been a lot of news reports that PR countries are experiencing rises in populism and whatnot, yet nobody seems to discuss the possibility of expelling the maligned parties (if they truly are dangerous.)

1/3 is a very high bar for an inclusion threshold. Being approval based makes it easier, but voters are not going to restrain themselves to using disapproval to keep out Nazis and other extremist groups, they’ll use it to keep out ordinary rivals. For example, regional interest parties (including, but not limited to separatist parties), which are the rare type of minor party that can survive and even thrive in FPTP, would likely be completely excluded under this system if approval was determined nationally, because voters outside of the region and major national parties tend to find them annoying. Since these parties often thrive in regions that believe that their interests are being ignored by national leaders, denying these parties any representation when they are very strong within their region will only increase their supporters’ feelings of disenfranchisement.

Is there a better way to do an exclusion procedure? The way I see it, a 2/3rds majority of voters could likely opt to switch away from PR to another system, or to make the PR system less proportional (i.e. switch to MMDs or raise the electoral threshold), so it’d be fair for 2/3rds to ban or remove a party from power. Perhaps voters should be required to collect signatures, and only those parties for whom enough signatures were collected would be subject to an exclusion vote?

It could be made an absolute 2/3rds majority of all registered voters, though PR countries’ marvellous turnout weakens the effect of adding this in.

Just because voters can do something, doesn’t mean it is fair.

I don’t think exclusion is a good thing. A benefit I see to PR is that it can incorporate new movements and ideas into governance more quickly. 2 party dominated systems are often quite slow to incorporate them. Cardinal voting would be faster, by making it easier to defeat incumbents who refuse to evolve, but only once those ideas have gotten broad support. Voting systems cannot tell the difference between widely reviled extremist groups and new movements that are beginning to attract a following but are still mostly obscure.

How does cardinal PR compare to other forms of PR on this front?

Also, what if a 2/3rds majority could ban a party or set of candidates but only if they voted to do so for several elections (say 3)?

Perhaps a “policy ban” where voters can temporarily remove parties with certain policies? At what threshold would these be acceptable?

Could you provide an example of a party that might be or have been excluded under a 2/3rds majority currently but is/was good for their country? Can a party disliked by 2/3rds of the voters exercise any real power, and if not, is there any real need to exclude them?

Would you support removing a legislature’s ability to expel members with a 2/3rds majority?

Would the efforts to repeal PR in cities in the US in the 1950s have been as powerful if supermajority exclusion was enabled?

To put it another way, I think you can always get 1/3rds of the voters to respect the principles of proportionality enough to avoid abusing the exclusion power.

So annoying as to make significant efforts to remove them from office? My guess is that an exclusion power would likely force some reps to moderate themselves, but I see it more as a way to ensure that they remain productive members of the government rather than suppression.