Republicans are famous for accepting the unacceptable, arguing that whatever it is should be reduced a little rather than be abolished. From Eric Peters at ericpetersautos.com:

President Trump says he want to “go back, probably, to a 2020 standard” as regards federal mandatory miles-per-gallon edicts – the latter being the right word because it’s the honest word.
A “standard” is an objective value of some kind, used to evaluate whether a given thing rises to that standard. Federal Corporate Average Fuel Economy (CAFE) “standards,” on the other hand, are nothing more than the federal government decreeing that all new vehicles must average an arbitrarily laid down minimum miles-per-gallon. Those that do not average say 35 miles per gallon – the standard in force in 2020 – are considered “noncompliant” and their manufacturer is punished for this via fines that are imposed for offering such “noncompliant” cars for sale.
Note the offering part.
It often – it almost always – passes without comment that no one is forced to buy a vehicle that does not average 35 MPG. People are free not to. But they aren’t free to buy a vehicle that averages less than 35 MPG in that it’s not “free” when you’re made to pay more for something. Sure, you can buy a new car with a six cylinder engine. But you probably can’t afford to – because CAFE fines have made six-cylinder-powered cars luxury-priced cars and most of them no longer come standard with sixes anymore, either.
