This NYT article[1] discusses the problems New York Democrats are having with their primary system. If they use first-past-the-post, given a large field, they end up with candidates supported by only a minority of voters, who in turn are an even smaller minority of Democrat voters. So they have had a runoff system when no candidate gets 40 per cent of the votes, but this has caused divisions and delays.
The solution is obvious: adopt the instant runoff/single transferable vote/optional preferential system, listing favored candidates in order of preference and omitting those for whom you don’t want to indicate a preference.
Obvious as it is, this idea is almost certainly unsaleable in the US context. For reasons I don’t fully understand, the US, which was once the pioneer in all kinds of institutional innovation ( the primary system itself, for example, or decimal currency) is now intensely conservative about such things. The NY Dems have been radical, by US standards, in going as far as a runoff, and according to Wikipedia only outliers like Ann Arbor and San Francisco have been willing to try the instant runoff system.
More generally, in looking at the US, I’m struck by the fact that, with so many independent jurisdictions at all levels, there isn’t more institutional variation and experimentation. For example, all 50 states share the Federal model of a bicameral legislature and separately elected executive, even though there’s no requirement for this. I assume this is an example of institutional isomorphism, but I don’t know if there is any literature on how the process works in this case.
fn1. The NYT has just gone pay-per-view on its Op-Ed pages, and there does not appear to be a workaround for blogs. For me as a blogger, there’s no point in paying for something if you can’t link to it. So I probably won’t be linking to the NYT as much in the future, and only to news stories.