It was bound to happen sooner or later. Senator Clinton has begun revisiting the subject of health care. In speeches around the country, she sounds chastened. “I have to do what the political reality permits me to do,” the junior senator told the New York Times recently. Her message: “HillaryCare” and its 1,342 pages of heavy-handed regulations are gone. The pragmatic, problem-solving Hillary is here. Elect me president.

Whatever the reality, that’s the message, and it seems to be working. That illustrates well John Podhoretz’s argument in “Can She Be Stopped?” (Crown Forum, 254 pages, $26.95). Mrs. Clinton is “older and wiser and cleverer – and therefore more dangerous,” Mr. Podhoretz writes. “She’s shown the most important quality a successful politician can have: She’s learned how to adapt. She’s learned from her mistakes. And she’s even managed to make her mistakes work for her.” Like “HillaryCare.”

Mr. Podhoretz’s entertaining and brisk book – clearly the definitive brief for conservatives on Mrs. Clinton’s outlook for 2008 – shows that she will not just be a force to reckon with, but the odds-on favorite. Unless, that is, Republicans can stop bickering with one another and challenge her head-on.

Mrs. Clinton is the stealthy Democratic answer to President Bush. Mr. Bush campaigned as a “compassionate conservative” and flew under the radar until elected, after which he governed as a strong conservative. Hillary has taken pains to appear to move to the center – supporting the Iraq war, sounding hawkish, making nods to social conservatives on occasion – while signaling to the left-wing base that she’s still the same Hillary they love.

Her Senate record shows she’s still the same old Hillary. In 2005, she earned a rating of 96 of a possible 100 from Americans for Democratic Action, the definitive measure of who’s a political liberal and who’s not. ADA named her a “Senate Hero.” The votes talk and suggest what a new Clinton White House might look like.

Republicans who think Mrs. Clinton will founder on her husband’s scandals, on Clinton fatigue, on negative poll numbers, or the fact that she’s a woman are all wrong, Mr. Podhoretz argues. “Do not fight the last war,” he warns. Voters won’t blame her much for Bill’s infidelity, her supporters will view the conservative hatred as a positive, and the climate seems readier than ever for a woman to assume the presidency – provided she seems to be the safer of two choices.

How to get to Hillary? “Smoke her out,” Mr. Podhoretz writes. Despite being “the most famous person who is not now nor has ever been president,” Mrs. Clinton “maintains radio silence for long periods of time” during which she avoids controversy. That’s a way of trying to negate the great disadvantage of being a senator with presidential aspirations. Senators inevitably antagonize important constituencies; votes fall one way or the other.

Mrs. Clinton wants to have it both ways on the divisive issues like Iraq, tax cuts, and abortion. Conservatives need to foil that gambit. “This should be our cry,” Mr. Podhoretz writes, “‘We want to hear from Hillary.’ She must go on record.”

Among Mr. Podhoretz’s other stratagems: Make her vote on charged issues; make her criticize tax cuts; put her on record on trade and health care; suggest a U.N. pullout to see what she does; clean up Washington’s lobbying abuses, and nominate Rudy.

Nominate Rudy? Well, yes. Mayor Giuliani is extraordinarily popular, fondly remembered for his September 11, 2001, heroics, admired for his ruthlessness with unions and interest groups, and revered for turning around a crime- and corruption-plagued New York in the 1990s. Mr. Giuliani can overcome his disadvantage as an abortion-rights advocate by availing himself of the “unstated policy of the prolife movement that every politician gets a chance to change his mind on the matter.”

Like he does for anti-Hillary strategies, Mr. Podhoretz makes the case for Mr. Giuliani compellingly, although the appeal of Senator McCain, the current front-runner, can’t be discounted.

One of the great variables in all this is expected Republican turnout, and by extension, whether Republican congressional majorities are safe in this fall’s midterm elections. Twice the author says Republicans are likely to keep both chambers of Congress this year, but this seems less true with each new National Journal report.

“You need to avoid the temptation that has begun to afflict members of the party’s more ideological branches – the temptation to threaten to break off, to secede, to run third-party protest candidacies. That will only get Hillary elected,” Mr. Podhoretz baldly warns. True, but irrelevant for swaths of the base who regard President Bush’s positions on immigration and the budget as no different from Democrats. Many seem ready to stay home or bolt. Where, they don’t know.

If Republicans prove more willing to splinter, there will be a danger of a Ross Perot-like figure hampering Messrs. Giuliani or McCain as Mr. Perot did to George H.W. Bush and Bob Dole (Or, for that matter, what Ralph Nader does to Democrats). In the coming two years we’ll see – and if Republican discontent manifests itself at the ballot box, the answer to Mr. Podhoretz’s question will likely be “no.”

Mr. Conway is an editorial writer at the Washington Times and a 2006 Phillips Foundation journalism fellow.