Roe v. Wade is a study in unanticipated consequences. By establishing a constitutional right to abortion, the justices of the U.S. Supreme Court no doubt thought they were settling the issue for good, accelerating a process of liberalization that was already under way in 1973. But instead of consensus, the result was polarization. The issue of abortion soon after, and for the first time, took a prominent place in national political campaigns. By 1980, both major political parties had adopted extreme positions—Republicans favoring a “pro-life” constitutional amendment to ban abortion, and Democrats opposing virtually all regulation on “pro-choice” grounds. Every presidential and vice-presidential nominee since then has toed the party line on abortion.
Polarization over abortion coincided with a period of Republican ascendancy. Since the parties split on abortion, the GOP has won five of seven presidential elections, and no Democrat has had a majority of the popular vote. Republicans took over the Senate in 1980, and both houses of Congress in 1994. Obviously, many other factors have contributed to Republican success, but it is hard to look at these results and conclude that abortion has been a winning issue for the Democrats. Thus, the politics of abortion has favored the party that opposes the court-imposed “consensus.”
Compounding the GOP advantage is what I call the Roe effect. It is a statement of fact, not a moral judgment, to observe that every pregnancy aborted today results in one fewer eligible voter 18 years from now. More than 40 million legal abortions have occurred in the United States since 1973, and these are not randomly distributed across the population. Black women, for example, have a higher abortion ratio (percentage of pregnancies aborted) than Hispanic women, whose abortion ratio in turn is higher than that of non-Hispanic whites. Since blacks vote Democratic in far greater proportions than Hispanics, and whites are more Republican than Hispanics or blacks, ethnic disparities in abortion ratios would be sufficient to give the GOP a significant boost—surely enough to account for George W. Bush’s razor-thin Florida victory in 2000.
Has the Roe effect borne itself out in practice? The results are mixed. In terms of reapportionment, the trend is decidedly in favor of Republican states. The 30 states George W. Bush carried in 2000 had 271 electoral votes, a bare majority. Reapportionment after the 2000 census increased that number to 278. In the 1980s, they were worth only 267 electoral votes, not enough for a majority; in the 1970s, 260. The trend continues: Of the 10 fastest-growing states in 2003-04, Bush carried nine in 2004. (One of them, New Mexico, went for Al Gore four years earlier.)
But Roe effect doubters can point to 2004 exit-poll results that found 18- to 29-year-old voters—i.e., those born after 1975, who correspond closely with the post-Roe generation—were the only age cohort that supported John Kerry over Mr. Bush, by 54% to 45%. Yet caution is in order in interpreting these results. The Roe effect does not predict that younger voters will be more apt to vote Republican than older ones, only than they otherwise would be. Putting the Roe effect to a real test will require a longitudinal look at these voters. How will their voting pattern change, as they grow older and more settled? In any given year, the youngest age cohort will include a high proportion of lower-income and never-married voters, both traits that are highly correlated with voting Democratic. Marriage, in particular, tends to correspond with conservative attitudes on abortion and other social issues, and therefore with voting Republican. According to 2004 exit polls, Mr. Bush outpolled Mr. Kerry among married voters, 57% to 42%, while Mr. Kerry beat Mr. Bush among singletons, 58% to 40%.