The death of Osama bin Laden — and the success of President Obama’s roll-the-dice decision to deploy troops to get him — may change the landscape of American politics in one surprising particular. When Obama runs for reelection in 2012, he’ll probably be strong where his Democratic predecessors have been weak — and weak where they were strong.

By now it’s clear that whatever domestic political advantage Republicans sought to gain from accusing Democrats of being “soft on terror” — much as previous generations of Republicans occasionally made hay by accusing Democrats of being soft on communism — has been spent. In the 2006 congressional elections, voters punished Republicans for badly waging a war in Iraq that the GOP had tried to justify as an extension of that war against terrorism. Now, Obama has done what George W. Bush failed to do: bring bin Laden to justice.

Obama has also kept his promise to end the combat participation of American forces in Iraq. What he will do next in Afghanistan is anybody’s guess, but if he withdraws a sizable number of troops — from a war whose goal grows murkier with each passing day — he’ll do so with substantial public support. Republican hawks will surely criticize that decision, but the odds are close to zilch that GOP presidential hopefuls will run on a platform of continuing the Afghan war — especially since Obama has taken out Osama.

Take Obama’s success in killing bin Laden, add to it Bush’s decision to wage a hugely expensive and unnecessary war in Iraq, and what emerges is indeed a somewhat altered political terrain. The Republican advantage in times of heightened national security concerns — a prominent feature of both Cold War America and America in the post-Sept. 11 era — has been substantially neutralized. (Not, of course, for the Republican right, for whom Democrats, Obama very much included, are weak on defense because they’re Democrats. If the facts get in their way, counterfacts have to be invented, as they were in the Swiftboating of John Kerry.)

But if Obama has neutralized the Republicans’ traditional advantage in foreign and military policy, he also largely forfeited the Democrats’ traditional advantage in domestic economic policy. Unless Obama plans some changes in economic policy as swift and surprising as the bin Laden raid, Democrats will go into the 2012 election with an economy that shows few signs of recovery and with equally few proposals to make it better. They will be opposing Republican plans that would make the economy radically worse by imposing unsupportable health-care costs on seniors and slashing public-sector investments. But the election will be more a referendum on Obama’s stewardship of the economy than it will be on Republicans’ economic nuttiness or Obama’s national security achievements (unless, of course, America falls victim to another terrorist assault).

In the early months of his presidency, Obama and his economic advisers failed to gauge the extent to which homeowner debt would cripple the construction industry and overall purchasing, as well as the extent to which the globalization of America’s major corporations and their markets would dictate that their hiring, when it resumed, would happen more overseas than at home. Even if the president had assessed these trends more accurately, it’s not clear he could have persuaded Congress to enact a public works program large and effective enough to take up the slack created by the domestic private sector’s failure to expand. But unless the president is willing to climb this hill now — at least by making the case for, say, a public infrastructure bank and for strategic public investments on a much larger scale than he has thus far — he goes into the election with no real plan to help the economy.

He’ll have a significant record of achievement, including a close-to-universal health-care law and a new generation of regulations on our otherwise out-of-control banks. For their part, Republicans are still busy cooking up bad ideas he can run against. That, plus his national security bona fides and a second-rate Republican opponent, may be enough to secure him a second term.

But unless Obama becomes as bold on the economy as he was in hunting down bin Laden, his campaign may not resemble Democratic campaigns of yore.

Strong on defense. Not much to say on the economy. Obama (or is that McCain?) for president.