By Harry Hamburg, AP By Kathy Kiely, USA TODAY WASHINGTON — Sen. Byron Dorgan, a veteran North Dakota Democrat, gave Republicans an unexpected opportunity to capture a Senate seat after he announced plans to retire Tuesday. Dorgan, 67, disclosed his ...http://www.usatoday.com/news/washington/2010-01-05-dorgan-senate_N.htmWASHINGTON (Reuters) - As Round Two of the US Congress' punishing fight over financial regulation gets under way this month, one big question is whether Senate Banking Committee...