Oh yes, they are mandated!
There is something called CAFE, Corporate average fuel efficiency.
Passed during the Carter era of fuel shortages.
Basically forcing American car manufacturers to be more fuel efficient.
Since then, the CAFE was raised regularly, forcing manufacturers to abandon V8, now even V6, and eventually get rid of gas altogether.
Limits set by Obama and Biden are impossible to achieve without EV.
Trump cut it down to more reasonable levels, but Biden made it even worse.
To achieve it, car manufacturers have to pay Tesla to include some of Tesla’s in their lineup (sort of).
That’s and only that way Tesla makes money! (with high Tesla prices, unbelievably, Tesla still basically looses money on their cars, but make profits due to these payments)
Now, when everybody makes some EV’s, Tesla profits plummeted!
Yet they still will not allow Diesel over electric hybrids. If they want to cure most of the fuel consumption problem this would do it. It would be a practical and logical compromise.
But they NEVER compromise. It is always from one extreme or the other. Logical compromises are taboo.