Both Sprint and Clearwire down over 20% since Tuesday

The Obama impact has come and gone this week after boosting Sprint (NYSE:S) and Clearwire Corp.(NASDAQ:CLWR) shares last week, since Tuesday both companies are down more than 20%, and it could get worse.

Sprint shares are really feeling the pain today after reporting losing 1.3 million wireless subscribers.

The nation's third-largest wireless provider (for now) said it lost $326 million, or 11 cents per share, for the three months ending Sept. 30. It had earned $64 million, or 2 cents per share, in the same period a year ago.

Both Sprint and Clearwire shares had run up sharply in anticipation of federal regulators approving their WiMax wireless joint venture. The Federal Communications Commission approved the deal Tuesday. The Sprint-Clearwire venture aims to deliver high-speed wireless service that's much faster than existing mobile networks.

The Street has yet to be convinced that the WiMax network is going to be a money maker.