Ok, the Congressman is a fool.

If the US Government decided to go balls to the wall and destroy bitcoin, then sorry bitcoin will die.

1. They could confiscate all bitcoins in the US and crash the markets.
2. They could have elite computer hackers target all nodes.
3. They could send in special forces covertly and destroy all ASICS warehouses, with explosives.
4. They could just compromise the 4 mining pool operators and make them double spend and freeze all new transactions. 
5. They could just threaten to bomb anyone that mines bitcoin.

Realize that if the decision to use force is ever on the table, then bitcoin is dead.

Bitcoin Energy Waste ensures that mining operation can not hide from government eyes.

Only Proof of Stake networks have the ability to hide from a world government intend on destroying it.