The gubbermint: -Do not mine block #13123313123123, that is a federal order.
The miners: -Sir yes sir!
You mean, "The mining pool: Yes sir!". As far as the miners are concerned, they're incentivized to mine on the most profitable pool, which is the one that censors no transaction.
They only need to send the order to the biggest 3 or 4 pools and there goes your decentralized mining.
The top 4 pools as we speak mine 75% of the blocks. This means that even if 4 pools started censoring transactions based on federal orders, there would still be 1 in 4 blocks that could ignore all the censorship bullshit. And at this point, the pro-censorship pools would have just accomplished loss.