The group’s analysis found that, in the eight politically-pivotal states that register voters by party, a significant number have left the Democratic party since 2008, with many choosing to register as independents. Over 825,000 registered Democrats in Colorado, Florida, Iowa, Nevada, New Hampshire, New Mexico, North Carolina and Pennsylvania have departed the party rolls since President Obama’s election in 2008, a much more significant share than the number of Republicans (378,000) who have done the same. Meanwhile, the number of registered independents has ticked upwards by 254,000.

“In 2012, Independents are likely to turn out in their largest numbers in 35 years, and President Obama will need those Independent votes even more than he did in 2008, if he hopes to be re-elected,” Third Way analysts Lanae Erickson and Michelle Diggles write in the report.

The Democratic decline is especially stark in Iowa and Florida, two early Republican primary states where Democrats have lost significant ground. In Iowa, the number of registered Democrats has declined 7.9 percent since 2008, while the number of registered Republicans has increased by two percent. In the Sunshine State, Democratic registration decreased by five percent, while Republican registration dipped 2.2 percent.