"This is a healthcare bill, not an abortion bill," President Obama told ABC News on Monday. That he had to say this, said so much. The same day, Dick Durbin, the Senate's second most powerful Democrat, told reporters that abortion "is going to be a major issue" ahead. "I hope," Durbin added, "we can find a way around it."

We still have not found a way around it. This country's dominant moral debate for the past three decades is now at the center of the most ambitious, albeit contentious, effort at social reform in about four decades.

Not since civil rights has an issue so enduringly divided and defined American politics. So it was Saturday night that Speaker Nancy Pelosi begrudgingly agreed to the most significant limitation on the procedure since late-term abortions were banned six years ago.

The House provision bans taxpayer-subsidized insurance from covering elective abortions and, controversially, prohibits any participating private insurer from covering abortion in their regular policy. This was some moderate Democrats' asking price for their support. And so it passed out of the House, 220 to 215.

Only about one tenth of women who have an abortion ask their insurer to fund the procedure, according to the Alan Guttmacher Institute. And yet, the provision was enough to instantly incite the debate.

Today's abortion wars tend to be settled by small battles. And both camps mobilize for every battle as if it was the war. It's the conflict that is certain. Regardless of who wins a battle, the war goes on.

And in this latest confrontation, how quickly the brinkmanship came. At least 40 Democrats have threatened to vote against the final bill if it contains the provision. Democrat Rep. Lynn Woolsey, co-chair of the Congressional Progressive Caucus, has actually floated the idea that the IRS should reconsider the tax-exempt status of United States Council of Catholic Bishops for pushing the abortion provision.

Meanwhile, on Monday, Nebraska Democratic Sen. Ben Nelson said that he might not allow the Senate legislation to proceed unless his party's leadership resolves the abortion issue. By Tuesday morning, Nelson was on NBC's "Today" show warning, "While there may be different views about abortion, I think there's a strong majority against using federal dollars to fund abortions."

Later in the day, Hotline summed up the views of liberal bloggers with the headline: "This Will Not Stand." The major editorial boards have now also weighed in. The New York Times wrote that the provision, "was depressing evidence of the power of anti-abortion forces to override a reasonable compromise." The Wall Street Journal wrote that, "the real importance of the abortion uproar is as preview of the politics that will dominate every medical coverage issue if ObamaCare becomes law."

The very cultural debates Obama has sought to avoid now may derail, but more likely delay, the paramount legislation of his presidency. In spring, Obama told reporters that the Freedom of Choice Act, a law affirming abortion rights, was not his "highest legislative priority." The warring factions have now elevated abortion to a presidential priority.

Healthcare, like modern American politics, is now too captive to the abortion debate. More than three-decades of argument, of litigation, of exhaustive, virulent and sometimes violent confrontations, have passed. And yet, we so easily forget, how little we have changed.

About one fifth of the public believes abortion should be legal in all circumstances. About one fifth says it should be illegal in every circumstance. And the larger middle believes it should be legal in limited circumstances. These fault lines have defined abortion since the Supreme Court legalized it in 1973.

Two years after Roe v. Wade, Gallup began to ask whether abortion should "be legal under any circumstances, legal only under certain circumstances, or illegal in all circumstances?"

In 1975, 21 percent said always legal. In 2009, no change. In 1975, 54 percent said mostly legal. Now it's 57. Then, 22 percent said always illegal. Now it's 18.

The constancy of abortion views does not mean it is without flux. For the first time since 1995 a majority--51 percent--said they were "pro-life" in the Gallup Poll. That was in the spring. By summer, the division reemerged. "Pro-life," 47 percent. "Pro-choice," 46 percent. Yet these entrenched divisions only appear to taunt conflict. Each side is out for unconditional surrender.

Abortion is America's undying and irreconcilable debate. It is the vacuum of modern politics. A policy quagmire. And yet, we know why. Abortion concerns the most central of concerns. Life on one side. Liberty on the other. What may be most remarkable is not the endurance of this cultural debate, but that abortion divides America so deeply, so constantly, that it holds hostage so many debates and also us.

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