Competitive top-of-the-ticket races and a nearly all mail-in ballot primary could spell record turnout in Colorado’s August 10 primary:

Most counties — 46 of 64 — are holding all-mail elections. As of early Wednesday morning, 436,382 Coloradans had voted: 222,938 were Republicans and 210,201 were Democrats, according to the Colorado secretary of state’s office. About 1.5 million mail ballots went out around the state.
Although there are just a few days left to vote, many counties are reporting that voter turnout already has surpassed the 2006 and 2008 primaries.
“We’re only about 10,000 ballots away from 2008. It’s probably going to be the highest turnout we’ve had for at least 10 years,” said Josh Liss, deputy of elections in Jefferson County.

Republicans and Democrats are both entertaining high-profile Senate primaries, with Sen. Michael Bennet seeking election in his own right following his appointment in Jan. 2009. Bennet was tapped to fill the remainder of then-Sen. Ken Salazar’s term following his promotion to Secretary of the Interior by President Barack Obama.

According to the Denver Post, there haven’t been this many contested primaries for the state’s highest offices in 36 years. Bennet, expected early on to cruise to victory against Democratic opponent Andrew Romanoff due to a large campaign war chest and endorsement from President Obama, now finds himself in a race that has become unnervingly competitive and increasingly negative since June. The two Democrats find themselves neck-and-neck in the most recent polls.

For the GOP, voter backlash against Obama administration policies and the explosion of the Tea Party movement, particularly in Colorado, was widely expected to drive turnout to much higher levels. Ken Buck and Jane Norton have sparred over who really represents the concerns of the Tea Party, going to the mat on issues like illegal immigration and amnesty–issues they see as “red meat” for not just Tea Party members, but mainline, primary-voting Republicans eager to pounce on the opportunity to reclaim a U.S. Senate seat.