Near the end of a town hall meeting in Johnstown, Pa., a woman arose to offer a passionate plea to Barack Obama to “stop these abortions.”

Obama’s response was cool, direct, unequivocal.

“Look, I got two daughters—9 years old and 6 years old. … I am going to teach them first about values and morals, but if they make a mistake, I don’t want them punished with a baby.”

“Punished with a baby.”

Obama sees an unwanted pregnancy as a cruel and punitive sanction for a teenager who has made a mistake, and abortion as the way out, the road to absolution and redemption.

The contrast with Sarah Palin could not be more stark. At the birth of her son Trig, who has Down syndrome, Gov. Palin said: “We knew through early testing he would face special challenges, and we feel privileged that God would entrust us with this gift and allow us unspeakable joy as he entered our lives.

“We have faith that every baby is created for good purpose and has potential to make this world a better place. We are truly blessed.”

Between the convictions and values of Palin and those of Barack, then, there is a world of difference. In the culture war that is rooted in religious faith, they are on opposite sides of the dividing line.

But more crucial than their conflicting beliefs is the political reality. This election is America’s last hope to reverse Roe v. Wade. Upon its outcome will rest the life, or death, of millions of unborn children. The great social cause of the Catholic Church and the Knights of Columbus, of the Evangelical and Pentecostal churches, of the entire right-to-life movement, hangs today in the balance.

Why? It is not just that Obama is a pro-choice absolutist who defends the grisly procedure known as partial-birth abortion, who backs a Freedom of Choice Act to abolish every restriction in every state, who even opposed a born-alive infant protection act.

Nor is it because Joe Biden is a NARAL Catholic who has been admonished by bishops not to take communion because he has, through his career, supported a women’s “right” to abortion, the exercise of which right has ended the lives of 45 million unborn.

Nor is it even because McCain professes to be pro-life, or Gov. Palin is a woman who not only talks the talk but walks the walk of life.

No. The reason this election is the last chance for life is the Supreme Court. For it alone—given the cowardice of a Congress that refuses to restrict its authority—has the power to reverse Roe, and because that court may be within a single vote of doing so.

Justices Antonin Scalia, Clarence Thomas, Sam Alito and Chief Justice John Roberts appear steeled to overturn Roe and return this most divisive issue since slavery to the states, where it resided until January 1973.

And John Paul Stevens, the oldest and perhaps most pro-choice justice at 88, is a likely retiree in the next four years. And there is a possibility Justice Ruth Bader Ginsburg, at 75, a survivor of cancer, could depart as did Justice Sandra Day O’Connor.

Thus, in the first term of the next president, there is a strong probability that one or two of the most pro-Roe justices will leave the bench. Replacement of even one of these two liberal activists with a jurist who has a Scalia-Roberts-Alito-Thomas record on the U.S. appellate court could initiate a challenge to Roe, and its rapid reversal.

Not only would that decision be a stunning perhaps irreversible victory for the pro-life cause, it would return the issue of abortion to Congress and the states, where numerous legislators are prepared to curtail if not outlaw abortion on demand in America.

Overturning Roe would re-energize the right-to-life movement in every state. In some, like California and New York, where it could not wholly prevail, some restrictions—i.e., no abortions after viability—might be imposed. Requirements such as for parental notification before a teenager has an abortion and that pregnant women be informed of what the procedure means and the trauma that often follows could be written into law.

If Roe goes, all things are possible. If Roe remains, all is lost.

Is there any certainty that John McCain, who set up the Gang of 14 to give Democrats veto over the most conservative of Bush judges, would nominate an Alito or a Roberts? No.

But there is a certainty that a President Obama would move swiftly to replace a Stevens or Ginsberg, or any other justice who steps downs or dies, with a pro-choice jurist. For support for Roe v. Wade is a litmus test in today’s Democratic Party, where the right to an abortion has been elevated to the highest rank in the Constitution.

Bottom line. If Obama-Biden wins, Roe is forever. If McCain-Palin wins, Roe could be gone by the decade’s end.

As Catholics are the swing voters who likely will decide this election, one awaits the moral counsel of the Catholic hierarchy.