The only thing consensus can do is use hashing power to vote on using a chain made of blocks which is has already been determined to be mathematically consisten

The only thing consensus can do is use hashing power to vote on using a chain made of blocks which is has already been determined to be mathematically consistent by enormous amounts of hashing power OR to roll back that chain and continue it from an old spot. The only way to pull that money back from the US Gov would be to roll back all transactions and block creation up to the point they took control of those bitcoins. But doing so would be catastrophic- so you would never get miners to agree on that.