The flaws of FPTP voting are generally well known at this point. Extremely popular policies are given no platform in the US two party system. But could a grassroots network of vote compacts negate the spoiler effect?
A big-tent psuedo-party could hold a parallel primary before elections, agreeing to use all votes for a candidate if a critical threshold is reached. A green light candidate would need 51% (+ X% margin) of internal votes and ~40% of total election votes (varying by historical election turnout). Otherwise the voters default to least evil of the two party system.
The first question is legality, which I have no clue on. However, political parties are built on the idea of shared voting power, so I don't see how any argument against this scheme would make sense.
The second question would be logistics. Validating public voter identities is easy enough, but there would need to be a system of representative conventions to maintain trust. A local group proving unity by winning a local election would grant them access to a higher tier, up to the national level.
Obviously there are more complexities in reality (eg: the US electoral college, real life voter loyalty, etc...), but could it work?
Fully agree, but posted this more as theory on a potential way out of a two party hegemony. It also requires a lot of time and trust building to have any effect, so probably not applicable to US's current crisis. But there are a lot of countries that still use FPTP in some fashion, it might be applicable there.