On the eve of Colorado’s Aug. 10 primary, Public Policy Polling released the results of its latest poll (pdf) conducted over the weekend (Aug. 7-8) that indicates extremely tight races for both GOP Gubernatorial and U.S. Senate primaries. The Democratic U.S. Senate primary results give appointed Sen. Michael Bennet a bit of breathing room, but all three races still possess a large, untapped “undecided” response that could push the results later into the night on Tuesday:

Democratic U.S. Senate Primary:
Sen. Michael Bennet 49
Andrew Romanoff 43
Undecided 9
GOP Gubernatorial Primary
Scott McInnis 41
Dan Maes 40
Undecided 19
GOP U.S. Senate Primary
Ken Buck 43
Jane Norton 45
Undecided 12

Democrats and Republicans are running up voter turnout, with Democrats already exceeding recent primary numbers, and Republicans closing in on the high-water mark of 2004, when former Rep. Bob Schaffer lost to Colorado beer baron Pete Coors.

Total returned ballots by party through 3pm Friday, according to the Colorado Secretary of State:

Democrats–245,477

Republicans–269,646

Monday’s totals will be available after 3 p.m. MDT.