As President Obama approaches his second inaugural, one thing has become clear: The 2008 peacemaker politician has emerged as a skilled guerrilla warrior. If Bill Clinton’s tactical legacy was disarming his opponents by stealing their ideas — welfare reform, “personal responsibility,” cutting spending — Obama’s may be his skill at dividing to conquer his Republican foes.

Conservatives were once the reigning champs of honing in and exploiting an opponent’s weakness. Under this President, Lee Atwater’s Sun-Tzu quoting descendants have met their match.

Republicans are gamely trying to spin the fiscal cliff deal as a victory — 99% of the Bush tax cuts enshrined as permanent! But here’s what Obama got: A pass on entitlement reform (which now recedes to the “unlikely” category even as debt-to-GDP ratios threaten the economy); the public triumph of his election-year narrative that taxes are about “fairness” not economic growth; and a chance to divide Republican ranks between those fearful of being blamed for economic chaos and those fearful of losing conservative supporters.

MORE: Sorry, Wall Street. You’re stuck with Jack Lew

The landmines of Obama’s fiscal-cliff victory were planted by likely Treasury Secretary nominee Jack Lew — in the 2011 debt ceiling deal that put taxes and military spending cuts on the table, and left entitlement reform off, thereby ensuring Republicans would be operating on the defense. And that’s where they will be once again as we lurch to the next series of fiscal crises, starting with next month’s debate over raising the nation’s debt ceiling.

Republicans can threaten to shut down the government if the White House doesn’t agree to control spending. But just as polls showed during the fiscal cliff negotiations — and during the 1994 government shutdown — public blame likely will come crashing down on them. Already, Obama is acting like a president who knows he has the upper hand — telling the House Speaker “spending isn’t the problem” and suggesting he wants to raise more taxes by capping deductions.

In crafting a way forward, Republicans should study another Obama guerrilla tactic — this one from the 2012 campaign. The Obama campaign handed Republicans a pistol to aim at themselves in the form of its rule forcing Catholic organizations to offer birth control in their health plans. At the time, the rule seemed politically dumb: Why pick an election-year fight with the Catholic Church — and its powerful voting block?

In retrospect, the tactic was brilliant, slipping the words “birth control” into the Republican primary water table when none of the GOP candidates wanted to talk about it. Unlike abortion (Gallup shows a slim majority of Americans describe themselves as “pro-life”), birth control is a nearly universally-accepted fixture in American lives.

MORE: Good luck estimating your new tax rate!

So what better way to paint the GOP as extremist than to suggest the party wants to take birth control away from women, especially independent single women who will help decide the next presidential election? And, with staunch social conservatives in the race, why not let the party self-implode? No fingerprints needed.

Right on script, leading GOP candidate Rick Santorum became the poster boy for the view that birth control is immoral and doesn’t need to be covered by insurance. His attempt to parse the personal from policy — insisting he didn’t plan to take birth control away from millions of women –failed miserably, tarring the GOP and adding to the party’s many self-inflicted wounds with voters in 2012.

The historical irony here: Modern conservatives have long used the imagery of guerrilla war in their pursuit of politics, from Reagan revolutionaries in the 1980s celebrating the movie “Patton” (“Wade into them! Spill their blood!”) to former Speaker Newt Gingrich asking potential candidates if they were ready to be Jedi knights against the Darth Vaders of liberalism. Here’s Ralph Reed on the surprise rise of the Christian right he helped lead: “I paint my face and travel at night. You don’t know it’s over until you’re in a body bag.”

Of course, the left have had their own guerilla strategists, especially the late community organizer Saul Alinsky, whose “rules for radicals” focuses largely on how to dissect and defeat political opponents. “Power is not only what you have, but what the enemy thinks you have,” is one.  Another: “Pick the target, freeze it, personalize it, and polarize it.”

President Obama rose to political fame on a promise to unite red and blue America. He spent his first years in office end-running Republicans — on the stimulus, on healthcare reform, on Wall Street regulation. Now, emboldened by his re-election, he has figured out how to divide and weaken his foes.

As GOP leaders look toward the next series of fiscal crises and entertain explosive talk of government shutdowns or defaults, they shouldn’t forget the past year’s lesson: Beware when this White House is handing you a suicide pistol.