National Review editor Rich Lowry makes the case that Republicans can repeal health care reform if it passes:

Obama's original choice for health-care czar, Tom Daschle, warned Democrats long ago that bulldozing reform through on a narrow basis would make it liable to repeal. He cited the example of Australia, where reforms were passed, repealed, and passed again throughout the 1970s and 1980s. In the U.S., Obamacare-style insurance reforms were passed, then fully or partially overturned in Kentucky, New Hampshire, and Washington after those states suffered spiraling premiums and insurance-market meltdowns.

I don't know anything about Australian health care reform, and I suspect Lowry doesn't either. This article in Health Affairs about the Australian system suggests that his analogy is a very poor one. The Australian parties have jostled over the shape of health care reform -- conservatives favor an Obama-style program relying on private insurance, and liberals favor more of a Medicare-type approach -- but universal health care was never repealed:

Labor’s election victory in late 1972 led to the establishment of Medibank, a compulsory and universal health insurance system many of whose features are incorporated in the current Medicate system. Opposed by the organized medical professions and by non-Labor state governments, full implementation of the program in all states was delayed until October 1975, when the last state signed a Medibank agreement to accept the carrot of fifty-fifty hospital cost sharing with the federal government. In December of the same year, Labor was defeated by the Liberal/ Country coalition. In the election campaign, the leader of the Liberal party promised to maintain the popular new Medibank system, despite his party’s former opposition. The promise lasted less than a year, with changes in October 1976 heralding a series of policy changes that had effectively dismantled Medibank by the time Labor again won office in 1983.
The major modifications to Medibank were designated as Medibank II, III, and so on, but while the program retained the original name, it came to look quite different with each of the conservative government’s revisions. These changes both supported the ideological views of the government in power and formed part of its macroeconomic strategy. Changes were justified in terms of freedom of choice (of private insurance as an alternative to Medibank) and of reintroducing markets into health care.

More importantly, policy change is procedurally simple in Australia -- unlike the United States, which has multiple checks and balances plus a supermajority requirement to implement changes like repealing health care. Australia could completely re-write its health care system with a simple flip of party control, but that can't happen in the U.S. (We'll make some conservative advocates of Senate reform yet.)

Second, Lowry is utterly incorrect that "Obama-style insurance reforms" have been passed in Kentucky, New Hampshire, and Washington. Lowry's talking about state plans to just impose a small part of Obamacare -- regulations requiring that insurers not discriminate against people with preexisting conditions. As advocates of comprehensive reform have been saying, when you try to impose piecemeal regulatory reforms without bringing everybody into the system and subsidizing coverage for those who can't afford it, the whole system quickly falls apart. This is an example of the failure of reforms Obama's opponents have urged him to do as an alternative to what he is actually proposing.

The closest thing to Obamacare in the United States is the plan enacted in Massachusetts. It was put into place by Mitt Romney, who National Review endorsed for president in 2004, and is still defended by current Tea Party darling Scott Brown. In the last poll, 11% of Masschusetts residents favored repeal. I don't think it's going anywhere.

On top of that, in every other advanced nation, universal health care schemes (almost all of which are far more government-intensive than Obama's plan) are durable and popular. Conservative parties in such countries run on slogans like "Tories Will Cut The Deficit, Not The NHS." Lowry might argue that the United States is "exceptional," and perhaps Massachusetts isn't really part of America. But the same phenomenon has happened here with Medicare, a single-payer health care plan right-wing which Republicans are currently trying to protect by imposing a new supermajority requirement to cut a single dollar from it.

Medicare is different than Obama's plan, and not just because it's far more left-wing in its design. Medicare enjoyed a great deal of Republican support in 1965, wheras today's far more partisan and right-wing version of the GOP unanimously opposes Obama's considerably more moderate plan. Lowry focuses on the fact that Medicare's Republican support protected Medicare. I think the more important dynamics is that it protected Republicans from the accusation of opposing Medicare. If health care reform passes, Democrats are going to have a clean shot at Republicans  for years or even decades to come. The principle of universal coverage may be difficult to enact in a political system gripped by stasis and special interest capture. But, once in place, allowing all citizens access to regular medical care strikes nearly everybody as an obvious requirement of civilized society.