51.7% in 2004
1,101,255 out of 2,130,330

Source: FEC tables

Colorado

Electoral College (9)

Senate: 2002-2008: Wayne A. Allard (R)
Senate: 2004-2010: Ken Salazar (D)

March 19th, 2008
Rasmussen Reports Poll Election 2008: Colorado Senate puts Udall 46% Schaffer 43%