Could The U.S. Gov't destroy Bitcoin by owning it all?

You know the government is not fond of bitcoin, especially w/ a lot of illegal activity using it.

My questions is what would happen to the crypto-currency if the U.S. went on a massive buying campaign to buy/mine all bitcoins they could get their hand on and other cryptocurrencies? -- Essentially cornering the market? They have the resources to do so, and sure more bitcoin would always hit the market, but would this curtail it's popularity?