Huh? They need:
(1) a simple majority of each legislative house in Idaho, which is 18+36=54 people
(2) a simple majority of each legislative house in Colorado, which is 18+33=51 people, and
(3) a simple majority of each House of Congress, which is 51+218=269 people
for a total of 269+54+51=374 people. Your 320 million estimate is off by about 6 orders of magnitude.
(Even if you make the rather unrrasonable assumption that they need to convince enough unique voters to guarantee the election of a sufficient majority in each involved legislature—i.e., you assume that every eligible voter treats every Idaho, Colorado, and federal legislative election as a single issue referendum on the issue—you’ll find that the number is a very small fraction of the ~240 million eligible voters in the US.)
wouldn't such flexibility/decentralization hurt national competitiveness vis-a-vis say, u.s vs china, or russia etc?
It would also allow the states to serve their original role as “the marketplace of ideas”. One could imagine Oregon implementing state-run healthcare or a UBI, or Kansas implementing the “Fair Tax”, whereas now the states look to the federal government to implement these sorts of large policy changes.
Consider the situation in Oregon, where five rural counties have voted to leave the state of Oregon and to join the state of Idaho.[0] According to WaPo:
> "Lawmakers in Oregon and Idaho would have to enact bills to redefine the states’ boundaries and redistrict their legislatures. They’d also have to muster the votes to override a potential veto from their respective governors. And then Congress would have to sign off on the move."
In other words, these counties can only change states if they're able to get 320 million people to sign off on the change. That's crazy.
Now, how to achieve this in practice? Ideally we would revert to the original Federal system (with a small, weak federal government and strong state governments) and allow for counties to move between states, but that seems unlikely.
Alternatively, we could allow for counties to move between states, and allow States to self-organize into new federal/confederal nations, or to move between nations via some established process (i.e. referenda). These nations should coordinate at a supra-national level (like the EU) to facilitate commerce and free movement, and to allow for the settlement if nation-level disputes.
[0]https://archive.is/l3tJG#selection-565.166-565.444