a 30% US mining tax will be one of the best things to happen to bitcoin.
it will drive competition for blocks outside of the US.
it will distribute mining to micro size farms that blend in with daily usage
it will further prove the anti fragility of the bitcoin network
it will force greater distribution of mining pools
it will show all other industries that their electricity usage can also be discriminated against if they cross the government
it forces the gov to finally show it's hand