Nah, there doesn't need to be any federal government involvement whatsoever. There's an approach going on where states agree to vote for the national popular vote winner in the electoral college, if states with sufficient electors all decide to get in on the scheme. If enough states agree to this approach, the national election becomes popular vote only rather than our crazy map-based elections.
A similar scheme could be adopted via STV. STV ballots are all aggregated by a multi-state committee -- these things already exist to deal with things like water and energy rights. The election is then run on a really big computer (seriously, I've written STV software, it's kind of a slow algorithm). All electors from those those states go to the winner of the STV election. Alternatively states can run their own STV elections and they just be assigned electoral college votes of that state.
I've also run an STV election by hand to pick a committee chair. That took like 10 minutes to calculate, lol.
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A similar scheme could be adopted via STV. STV ballots are all aggregated by a multi-state committee -- these things already exist to deal with things like water and energy rights. The election is then run on a really big computer (seriously, I've written STV software, it's kind of a slow algorithm). All electors from those those states go to the winner of the STV election. Alternatively states can run their own STV elections and they just be assigned electoral college votes of that state.
I've also run an STV election by hand to pick a committee chair. That took like 10 minutes to calculate, lol.
-- ∇×V