It's official: President Obama is on his comeback tour. Charles Krauthammer even goes so far as to say that Obama has won The Triple Crown, in getting a tax cut bill passed, Don't Ask Don't Tell repealed, and the New START treaty approved. As Krauthammer puts it, Obama "came back with a vengeance," leveling the field with the new Congress.

But is it true? Did passage of Start allow Obama himself to get restarted? Did the GOP blunder by signing on to the tax bill?

Certainly Obama seems to be taking nothing for granted. He's engaging in a major shakeup of his administration. The New York Times reports that David Plouffe, who headed the 2008 campaign, is returning to the White House, while Press Secretary Robert Gibbs is set to either leave the administration or become a senior adviser. Obama is also looking for a new head for the National Economic Council. It seems clear that vice-president Joe Biden's influence keeps rising as well. He's Obama's link to the Senate, where the Democrats continue to hold a slender majority.

All this is very different from the Jimmy Carter years. Carter's grave personal flaws--his petulancy, flip-flopping, and penchant for blaming the American people for economic woes--doomed his presidency. Obama is doing none of that. His flaws are different--professorial lecturing and what David Bromwich calls his general fastidiousness.

But with passage of Start, Obama did show a different side, one that indicates he is ready to fight for what's really important to him. Republicans will thus have to play their cards carefully. Had the GOP held out against any compromise during the lame duck session, Obama would have pilloried the party as a bunch of do-nothing legislators, a tack that Harry Truman successfully followed in his 1948 reelection campaign.

The truth is that playing field may be level, as Krauthammer puts it, but that was probably inevitable. The power of the presidency remains enormous, particularly in a time of war. Sen. Mitch McConnell overreached in trying to stymie Obama on Start, which, as Krauthammer notes, ended up inadvertently handing Obama a big PR victory over a small treaty.

But the real arena of contention in the next two years will not be foreign policy. It will bethe deficit and economic regulation. The administration is issuing a raft of new environmental regulations on emissions under the flag of combatting climate change--a tailor-made issue for the GOP to argue that liberal government bureaucrats are being empowered by Obama to run roughshod over the free enterprise system. Similarly, the GOP can take a number of steps to push for deficit reduction--if it wants to. That would have to include cuts in the Defense budget as well as social programs. The looming collapse of state pension fund systems will also allow the GOP to the imperative of slashing deficits.

So, yes, Obama has made something of a comeback. If the economy continue to recover, it will be extremely difficult to unseat him in 2012. But that doesn't mean that the GOP won't be able to stymie much of his legislative agenda in the next two years.