The economy dominates the 2012 electoral landscape, but social issues like abortion lurk in the shadows. By short-circuiting the political process with its 1973 opinion in Roe v. Wade, the Supreme Court turned abortion into the nation’s most divisive election issue.

Next week Mississippi voters will decide on a constitutional amendment defining a person as “every human being from the moment of fertilization, cloning or the functional equivalent thereof.” Similar efforts are underway in Florida, Ohio, and Wisconsin.

Critics charge that such measures could limit birth control and medical treatment as well as discourage abortion. A court challenge is certain. Author Jessica Valenti complained that “Personhood advocates are interested in only one kind of ‘person’.”

However, the campaign to define personhood is a strategy of desperation. America’s cultural and political elite has spent years promoting abortion by means foul and fair. Abortion advocates value sexual freedom more than the life which may result from sexual freedom. For many of them, life is cheap and disposable, with an “unwanted” baby but an inconvenience to be swept away. There is no other “person” or interest to acknowledge, let alone respect.

Abortion is a difficult issue. Restricting liberty to save life is never an easy trade-off. Many of those who desire an abortion are in difficult circumstances. Certainly government intervention is a poor second best.

However, while a woman should control her own body, a baby is far more than just “a woman’s body.” Birth marks the moment of physical separation, but the baby’s individual identity and unique moral worth are established long before. Nor does “viability” have much significance in principle. The baby’s life is distinct when gestating within the womb.

Even many abortion advocates grow uncomfortable once the fetus begins to look like a baby. Sen. Daniel Patrick Moynihan, for years one of Washington’s celebrated liberal intellectuals, found late term abortion to be “too close to infanticide.” However, legal protection should not depend on appearance. It takes time before a fetus looks human, but once the fertilized egg is implanted it will develop naturally into a separate person. To abort is to kill what will shortly become a child, acknowledged by all to have the same right to life as any adult.

Some pro-life activists call abortion murder. However, “murder” is a legal term of art with extraordinary emotive power. It poisons the debate, since disagreement over the moral equivalence of a fetus to a human being is the very issue in dispute. Abortion is abortion, a different and much disputed form of killing.

Still, whether a baby is a separate “person” or not, abortion advocates maintain that women have the right to eliminate it at will. That would be the case if the fetus was simply a growth. That also would be the case if the baby showed up uninvited. However, except in the case of rape, pregnancy is preceded by an important voluntary act: sex.

Obviously, that doesn’t mean babies always are wanted, especially at a particular time. But anyone who has sex knows that pregnancy can result. Even the best birth control is not foolproof. Having chosen to enjoy the pleasures of sex, one should not expect to avoid the act’s less welcome consequences. The point is not to penalize everyone everywhere for enjoying life. Rather, liberty requires responsibility. Sex is a matter of choice; abortion is an attempt to avoid accountability.

If people are unwilling to accept responsibility for their actions, then the state has a duty to step in. It can stop parents from abusing their children; it can stop a mother from aborting her baby. Of course, the principle sometimes is easier to state than to apply. What exceptions? Rape and life of mother, certainly. What penalties for whom? Sanction doctors more heavily, probably.

The result should leave any advocate of a free society feeling uneasy. Government intrusion in such a personal area is a last resort. However, it also is a necessary resort. People have no obligation to bring another life into being. In fact, people can take every precaution not to create a new life. But if their voluntary actions — by accident or design — result in a baby, they do not have the unrestrained and unreviewable right to kill the new life. Indeed, the first obligation of government is to protect those unable to protect themselves.

Americans have been moving in this direction. Poll numbers vary over time, but of late pro-life voters have taken the lead. Nevertheless, pro-abortion forces dominate the White House, Senate, judiciary, and media. Pro-life Democrats, who included Richard Gephardt, Al Gore, and Bill Clinton before they all ran for president, made a brief renaissance in Congress, but were nearly wiped out in the 2010 election. Today the main area for activism is the states, hence the personhood initiatives.

Such measures are imperfect. However, the judicial takeover of the issue has left pro-life advocates with no choice. Roe v. Wade was issued at a time when the Supreme Court was busy rewriting the Constitution to reflect its own preferences. Abortion was legal when the 14th Amendment was passed, yet more than a century later the high court discovered principles hidden therein to void every abortion law in the nation. The decision was the apogee of so-called “judicial activism,” when jurists confused liberal politics and constitutional law. In fact, the ruling in Roe read like a piece of “Great Society” reform legislation, not a legal decision interpreting the nation’s foundational law.

Two years ago President Barack Obama admitted that “abortion is never a good thing.” He was right. Every abortion is a tragedy.

Nevertheless, government interference with the sort of personal decisions involving pregnancy requires a strong justification. Babies have entered the continuum of life and should not be disposed of when viewed as inconvenient. Bringing a new life into the world creates obligations that cannot be abandoned at will. Abortion is not a choice to be made. Rather, it is flight from responsibility for a choice previously made.