Justice Sandra Day O’Connor’s decision to step down from the Supreme Court sets up a possible next chapter in the nation’s culture wars. If the debate over O’Connor’s replacement turns into a referendum on Roe vs. Wade, the landmark 1973 decision establishing a woman’s right to abortion, the argument is likely to galvanize a significant portion of the American public.

But typically, Supreme Court nominations are not followed closely by large percentages of Americans. The controversial nomination of Clarence Thomas in 1991 was very much an exception in this regard. About two-thirds of the public (66%) was engaged by the battle over Thomas’s nomination in the summer of that year; by contrast, only about four-in-ten (43%) had followed news of David Souter’s selection a year earlier.

Opinion about Roe vs. Wade is highly politicized, but the public overall continues to strongly oppose the total reversal of the Roe vs. Wade decision. By 63%-30%, the public rejects the idea of completely overturning Roe vs. Wade. That margin has remained stable for more than a decade.

In many ways, the political divide over that landmark court decision reflects the potential battle lines over O’Connor’s replacement. Solid majorities in most demographic groups oppose completely overturning the Roe vs. Wade decision, but opposition is greatest among liberal Democrats (82%) and seculars (82%).

Conservative Republicans are by far the most supportive of overturning the Roe vs. Wade decision (62%). This represents a deep division within the Republican base, as Republicans who describe themselves as moderate or liberal favor maintaining Roe vs. Wade by a 71% to 25% margin.

If debate about O’Connor’s replacement is not framed with respect to the repeal of Roe vs. Wade, it is likely to mostly attract the attention of strong Republican conservatives and liberal Democrats. Pew’s political typology survey found that nearly six-in-ten Enterprisers (59%) say the choice is very important personally, as do roughly half of Liberals (49%) and Social Conservatives (47%). Fewer than four-in-ten in the other typology groups attach great personal importance to the choice of the next Supreme Court justice (see “Beyond Red vs. Blue,” May 10, 2005).

That study also found that a plurality of Americans (41%) believe that President Bush should choose someone who will keep the court about the same as it is now, while roughly equal numbers support a more conservative nominee (28%), or a more liberal one (24%).

Only two groups, Enterprisers (64%) and Social Conservatives (50%), clearly favor a choice that would make the court more conservative. In five of the other groups, pluralities ­ or, in the case of Upbeats and Disaffecteds, majorities ­ feel that the president should choose someone who would keep the court’s ideological balance about the same as it is now. Most Liberals (52%) would prefer a nominee who will make the court more liberal.