UPDATE: Restoration PAC, which came in for Glenn early on with an $800k media buy in July, has just put more behind the positive ad entitled “Underdog” in light of polling that shows Glenn gaining ground.

A shift ishappening in Colorado. Not only has the presidential race tightened to a statistical tie, but polling shows the U.S. Senate race – once thought by many to be a foregone conclusion – continuing to tighten in the final days of the election. So much so that Democrat Sen. Michael Bennet is nervous enough to go on the attack against GOP challenger Darryl Glenn. Michael Bennet

Until now, all of Bennet’s ads have been positive pieces about him and completely ignored Glenn. That approach effectively sent the message that Bennet didn’t see Glenn as a threat. And what a miscalculation that was. Though it seems unbelievable, Bennet actually managed to blow a 20 point lead, and we now see Glenn only 5- 8 points down (depending on which poll you’re looking at).   That means he is within striking distance if Republicans continue to close the turnout gap, which they have been doing.

By going on the attack, Bennet is not only admitting that Glenn is a viable candidate but that the race has migrated into competitive territory. And if we were Bennet, we’d be nervous too. Combine this polling news with Glenn’s killer fundraising and we’ve got a real nail biter on our hands, folks.