Elon built a power plant in Mississippi to run computers in Tennessee. They're a few hundred feet apart. The state line between them is doing all the work. Here's the trick. Air permits come from state regulators. Memphis fought his turbines for a year. So he put the new ones just over the line in Southaven, where Mississippi approved all 41 of them three weeks after the public hearing. Unanimous vote. The computers stayed in Memphis, because Tennessee has some of the cheapest power in…