How difficult (expensive, realistic, etc) would it be for the US gubmint to buy up enough mining power to hijack the network, change the rules, and send it all to zero?
I don't know how to do the calculation of the Hashrate power and how much it will cost the US to hijack the Bitcoin network but trust me if it is something they can do they would have done it a long time ago instead of some government saying negative things about Bitcoin and they also understand that crypto is inevitable.
With that being said, the US government has a lot on its plate in terms of debt and wasting some funds just to hijack innovative technology which has helped a lot of their citizen get a job will never be their next motive not even now that the institution is also an investor.