Did states' motor voter programs help the Democrats?

The National Voter Registration Act (NVRA) of 1993 required all states to establish "motor voter," mail-in and agency registration procedures prior to the 1996 Presidential election. Using state-level data for the 1976-94 period on party registration, we analyze the party registration impacts of state programs that were precursors to the NVRA. "Active" motor voter programs roughly similar to those mandated by the NVRA are found to significantly increase the proportion of registrants on the rolls who are unaffiliated with either major party. Mail-in registration shows no impact on party registration, while agency registration significantly increases the Democratic share of the two-party registration total -- despite the fact that most agency programs in our sample period were far weaker than NVRA mandates.