The change in voter registration in Colorado since the last Presidential election is striking. In 2008, for the first time ever, Democrats were at near parity with Republicans in registered voters in Colorado. Four years later, they are lagging behind badly with six months to go until Election Day.

In 2008, Secretary of State records show that Democrats had 1,056,077 registered voters, only slightly behind Republicans 1,069,497 registered voters.

As of April 1, 2012 that gap has widened considerably, with Republicans holding a 30,000 voter lead in total registered voters, but a whopping 120,000 voter lead in active voters.

The Obama campaign utilized the long and drawn out primary with Hillary Clinton to boost voter registration totals for Democrats in 2008, but without a primary this time the Obama campaign is struggling mightily to find ways to turn that around. 

Reports The Denver Post's Sara Burnett:

Faced with a voter registration disadvantage of more than 100,000 people – a number that has grown since the start of the year – President Obama’s re-election campaign spread out across Colorado over the weekend, trying to close the gap.  

The campaign held about 60 education sessions for volunteers between its 13 Colorado offices, Spokesman Michael Amodeo said. Those volunteers then walked targeted neighborhoods and high-profile areas such as Boulder’s Pearl Street Mall, asking people to update their voter registration.

The active voter registration advantage that Republicans have, and are continuing to build on, is a serious problem for the Obama campaign. With active voters voting at over ten times the rate inactive voters do, that gap is surely causing some serious heartburn at Obama HQ. 

As the race in 2012 is virtually guaranteed to be close in Colorado — the last poll had Romney and Obama tied at 47% — partisan turnout could be pivotal in swinging the state one way or the other. 

If Democrats don't fix the voter registration gap soon, they could be in serious trouble come November.