President Obama's recent comments on universal voting have spurred a debate about how such a policy would influence elections. On the Monkey Cage blog, John Sides examines the partisan consequences and argues that turnout would generally benefit Democrats, but that the effect would be modest. His own research, with Jack Citrin and Eric Schickler concludes, "Although Democrats fare better in each scenario, few outcomes would have changed." He does note that both the 2000 and 2004 elections would have been different with universal turnout.
While these questions are indeed interesting, I'm more interested in the policy consequences of universal turnout. After all, the most important political change in the last three decades hasn't occurred between parties, but rather within parties: the Tea Party pulling the Republicans right and a more wealthy and elite Democratic party abandoning union-type policies.
So what do we know about the policy consequences?