With the November elections on the horizon, numerous Senate Republicans broke from President Bush Thursday to help Democrats pass a $165 billion bill to fund another year of the Iraq and Afghanistan wars and a separate domestic spending package.

For Democrats, the 2008 primary season has been the longest in recent memory, with no shortage of upsets, talk of momentum, and states defying parties to hold primaries earlier than ever. Three historians discuss the significance of 2008's lengthy primaries.