Also also, I'm not the one who invented this ridiculous scenario of every state for themselves, that was OP.
The farms and just about everything else in "red" states are subsidized by the "blue" states. Their farms are not sustainable nor really competitive without those subsidies. They're completely financially ruined without subsidies and their largest customers. They're not going to be able to replace the "blue" states ports and neither Canada or Mexico are likely going to be interested in transporting their wares without hefty tariffs.
It's almost like the country works because various groups work together under common legal frameworks despite ideological differences and uncompromising culture ware is short sided idiocy.
It's not strictly an invention of the OP. The current administration is fully advocating for ripping away funding and benefits to blue states. In a world where the federal government is ensuring that the tax dollars these states pay do not benefit said state at all, there is no rational reason for said state to continue contributing to the union as opposed to clawing back those tax dollars and investing directly in their own state.
And of that, I cannot think of any countries that would encourage 'buy american' at the moment. I certainly don't.