Why Abortion Is Not Like Other Issues WASHINGTON - IT'S no secret that the Republican Party differs with public opinion on some of the day's biggest issues. Be it on gun control, immigration, same-sex marriage or high-end taxes, the party has advocated a position at odds with the beliefs of most Americans, polls show. This disconnect has helped Democrats win the popular vote in five of the last six presidential elections. The recent acrimony in the Texas Legislature, with Republicans pushing a restrictive abortion bill, seems to provide a new example. It has allowed Democrats to cast Republicans, once again, as out of the mainstream. Yet abortion is not quite like those other issues. On abortion rights, both parties have a claim on public opinion. Maybe more to the point, both can make a strong case that the other party has an extreme view. Abortion is the relatively rare issue in which the cliché is true: public opinion does actually rest about midway between the parties" platforms. As a result, abortion occupies a different place in the Republicans" continuing struggle about whether and how to modernize their party. On a set of other social issues related to the increasingly diverse American population, the party clearly faces big challenges. The two fastest-growing ethnic groups - Latinos and Asian-Americans - are decidedly liberal. Younger white adults also lean left. My colleague Nate Silver estimates that in the year 2020, ballot initiatives on same-sex marriage would pass in 44 states, based on the direction of public opinion. The only six states where the initiatives would likely fail are solidly Republican Southern states. Anyone following the Texas abortion debate through social media could easily imagine that the issue belongs in the same category. During her filibuster against the bill, State Senator Wendy Davis inspired a hashtag - #StandWithWendy - and a Twitter explosion. An often overlooked aspect of social media, however, is that it still skews slightly liberal. Nationwide, polls consistently show that people are no more "pro choice" than "pro life," when asked to choose a label. More detailed questions yield similar results. And women are no more in favor of abortion rights than men. "Abortion is not heading in either party's direction," says Andrew Kohut of the Pew Research Center. About 60 percent of Americans favor access to abortion in the first trimester (or first 12 weeks) of pregnancy, but close to 70 percent think it should be illegal in the second trimester, according to Gallup. Likewise, a recent National Journal poll found 48 percent of respondents favoring, and only 44 percent opposing, a House of Representatives bill that would ban abortions after 20 weeks of pregnancy except in cases of rape and incest. "About 8 in 10 Americans believe abortion is taking a life," said Ed Goeas, president of the Tarrance Group, a Republican polling firm. What you then have is a discussion about when it is acceptable. Perhaps the best weapon of abortion rights advocates is their opponents" extremism. The Texas bill, for instance, would close most of the state's abortion providers and ban the procedure after 20 weeks, without exceptions for rape or incest. A clear majority of Americans support such exceptions, as well as those for the health of the mother, polls show. Ilyse Hogue, president of Naral Pro-Choice America, says that while she is distressed by the recent spate of state laws, she thinks her side will ultimately benefit from the new focus on the issue. Not only do many abortion opponents favor tough restrictions on the practice; they also oppose in vitro fertilization, some forms of contraception and stem-cell research. Ms. Hogue argues that many Americans will find these arguments "wing-nutty." But supporters of abortion access have their own challenges. The issues on which it's easiest to predict the future of public opinion generally involve individual rights. Over time, rights - suffrage for women and blacks, job opportunities for Irish, Jews, Latinos and other ethnic minorities, marriage for interracial and same-sex couples - tend to expand in the United States. In the debate over abortion, unlike the debates over immigration and marriage, both sides can easily claim the mantle of individual rights. Supporters can maintain that women deserve the right to make decisions about their bodies at any point in a pregnancy - and that many abortion opponents change their position when facing a real-life decision. Opponents can counter with increasingly clear images from sonograms, often showing decidedly human forms on the cusp of viability. Opponents can also point to the specter of eugenics: one study has found that prenatal screening caused births of children with Down syndrome to be 49 percent lower than they otherwise would have been, even as medical advances have sharply extended the lives of people with the disorder. When fetuses with Down syndrome are aborted, it is typically after the first trimester. Those dueling claims probably mean that the debate over abortion is here to stay. As Mr. Kohut notes, polls show that young people - despite their general liberalism - are divided, much as their parents and grandparents have been. If the issue presents either Republicans or Democrats with a political opportunity, it is one they will both struggle to exploit, given the passionate feelings of their bases. But the opportunity does exist. Most Americans are uncomfortable with abortion yet believe there are circumstances - and not just a narrow few - when it should be legal. They believe that women should have control over their bodies and also that an abortion is akin to a death. Where they struggle is in deciding when each principle deserves to take priority. David Leonhardt is the Washington bureau chief of The New York Times.