Colorado’s largest eleven counties contain 84 percent of the state’s voters, but Arapahoe County will get the most attention. It voted for G.W. Bush in 2000 and 2004, but Barack Obama carried it by 9 points, his state average, in 2008. It has three targeted legislative races, a down to wire congressional race and is likely the linchpin of the state presidential race.
On election night, Democrats must carry large majorities in their three largest counties of Boulder, Denver and Pueblo. Similarly, Republicans need big votes in Douglas, El Paso, Mesa and Weld counties. The two swing counties of Arapahoe and Jefferson will likely decide the winner, which is why the candidates most frequently visited them, especially the last couple of weeks.
Also, Larimer County tends to lean Republican as Adams does Democrat. By how much in a close election will help determine the winner.
Small counties that lean Republican are Broomfield (33,000 registered voters), Fremont (21,000), Garfield (25,000) and Montrose (21,000). Democratic counties are Eagle (24,000) and La Plata (30,000). These six counties, the next largest after the top eleven, have 154,000 registered voters, which gives them a political clout slightly greater than Weld County (123,000).