One of President Barack Obama's great political gifts is his moderate demeanor — cool, reasoned, self-contained.

One of President Barack Obama's great political gifts is his moderate demeanor — cool, reasoned, self-contained. It masks the frank immoderation of everything about his final push on health-care reform.

His liberal admirers call him a centrist. He hasn't tried to pass a single-payer system, has he? But Obama is in Washington, not Ottawa. Single-payer couldn't possibly pass. Nor could the public option, which Obama supported until it reached its absolute expiration date. These aren't principled acts of centrism; they are unexceptional adjustments to reality.

Obama supports the leftmost plausible bill. It's as expansive and expensive as possible without getting so big it's utterly impossible to stuff through Congress. Obama has blessed the unsightly procedural contortions necessary to pass the bill — the reconciliation rules in the Senate, the "deem and pass" in the House — to avoid going back in the Senate and budging another inch to the center.

Who are the recalcitrant right-wingers Obama would have to placate to pick off one or two Republicans and get 60 votes again in the Senate? Olympia Snowe of Maine, who voted for a version of the bill in the Senate Finance Committee before Majority Leader Harry Reid lost her by pulling the bill back left again. Susan Collins, also of Maine, who is as pliable and prone to bipartisanship as Snowe. Obama just got 68 votes, including 11 Republicans, for a compromise $17 billion jobs bill in a Senate that we're told is irrevocably broken.

It's not as if a scaled-back bill was inconceivable. After the Massachusetts election, the White House prepared a Plan B covering half the uninsured at about a quarter of the cost of the current bill, according to a report in The Wall Street Journal. But compromise was anathema to Obama, even though persevering in support of the maximalist bill represents a desperate gamble out of a Dostoyevsky story.

If Obama loses on the House floor, it would be a legislative rebuke for the ages, on par with the impeachment of Bill Clinton or the sinking of the League of Nations after all of Woodrow Wilson's exertions. Obama's early presidency would lie in ruins. He would have kicked away the political middle with nothing to show for it, appearing both overly ideological and ineffectual in a toxic Carteresque brew. Obama is willing to court this disaster.

Even if he wins, he's risking untold damage to his party in the backlash against the audacity of it all. A smaller-scale bill would have given the Democrats a victory while leaving vulnerable members less exposed. Instead, they will be asked to give the last measure of their devotion. No cost is too great in the glorious cause.

Obama's increasingly heedless in his salesmanship. When he calls the bill a deficit-reduction measure, at least he has the backing of a Congressional Budget Office analysis that — taking all the bill's unrealistic assumptions at face value — says it will reduce the deficit. He has no serious warrant for his otherworldly claims that it will control costs and reduce insurance premiums. The provision he has dubiously touted as a solution to rising premiums, a federal review board, won't even make it into the final bill.

The president engaged in similarly shameless overpromising in hawking his stimulus bill. How did that turn out? He won't even mention the word "stimulus" anymore. On health care, his most alluring promises will soon be discredited, as costs, premiums and the number of uninsured (in the near term) remain high. To paraphrase Colin Powell, if you reform it, you own it, and all the discontents with the health-care system will now adhere to Democrats.

A more cautious and shrewd leader would avoid making easily falsifiable representations or putting himself on the hook in this way. Not Obama. On health care, he's immoderate in his substance, his risk-taking and his rhetoric. He's all in, and he doesn't care.

Rich Lowry can be reached at comments.lowry@nationalreview.com.