Central question w/ Kennedy's retirement is political impact of potentially overturning Roe. My new book "The Increasingly United States" (goo.gl/SgHtsb) provides a way to approach that. Key is to first recognize that nationalization can mean two different things. 1/n 
Politics can be nationalized when state, national divisions are over similar issues (figures on right side). But politics can also be nationalized when voters care only about nat'l issues, aren't engaged in state or local pol (figures on bottom). 2/n
These two sides of nationalization don't always move in tandem. Along the first dimension, nationalization rose in 1930s and 1940s, declined until ~1980, grew to new heights after. 3/n
Nationalization along 2nd dimension appears more consistent, with declining knowledge of govs, turnout in subnational races going back several decades. 4/n
What does this mean were Roe to be overturned? Abortion is a highly nationalized, symbolic issue--a flurry of state-level policymaking on abortion would potentially increase connections between vote choice across levels of gov't. Nationalization along the first dimension. 5/n
At the same time, it would also likely mobilize on both sides of the issue, and so heighten participation, engagement in state-level politics. Undercutting nationalization along the second dimension. 6/7
Am. pol. now often has a single, nationalized political agenda, with events in federal politics setting the agenda for the states (e.g. NCLB, ACA). Focus is on issues that resonate nat'ly. Overturning Roe, catalyzing state-level abortion debates wld reinforce that pattern. 7/7
