B. Except both parties have political machines... and government corruption has a real tendency in America to tick the voting public off.
Machines can be destroyed, especially under the guise of anti-corruption efforts. Anyways, if you look closer, government corruption tends to be forgiven quite easily by American voters. Just look at the Tea Pot Dome scandal, the biggest scandal in American history pre-Watergate, and it was only a minor inconvenience for continued Republican control of government. Watergate itself was a temporary speed bump in Republican dominance, and Iran-Contra wasn't even an inconvenience. That's the wonderful thing about cynicism - it makes gullible saps out of your public. An authoritarian regime would
want its people to think it's hopelessly corrupt - so long as they also think that all government is hopelessly corrupt, as Americans tend to, they won't lift a finger to change anything.
There's also the fact that different heavily populated regions of the country have often had clashing interests (For example, that other region of the country just north of the region you mentioned),
And those could be managed exactly like America has done so OTL, through a combination of bribery with pork, dividing the residents of each state against themselves, and the memory of the Civil War impeding actual secessionism. Only here, a whole new universe of coercion is also available, so the menu of options has only gotten bigger.
and free enterprise which will naturally resent any government attempts to form oligarchies like Russia's state owned companies.
You assume they won't, in fact, be the main beneficiaries of such a regime. Or that they couldn't be divided and ruled just like Russia's OTL companies.
It was possible to build "managed democracy" in Russia because the country had been essentially reduced to ashes following the collapse of the USSR and the mass liquidation of essentially all the nation's capital: such a scenario, while possible, is VERY unlikely to occur in the USA without producing a situation that's so mind-bendingly bad that its unlikely the nation would even still be together in a recognizable form.
And in America, we got to the same place for about two and a half years IOTL through a combination of war measures, xenophobia, extralegal government enforcers with zero transparency, and the inherently paternalistic mindset of the progressive movement, which wanted all along to put power in the hands of technocratic managerial types. You're so fixated on the Putin lens that you only see the distinctions in the American factors that count against replicating that specific oligarchy, while ignoring the differences that would work in favor of a racist, red-baiting Palmerfeldia.