Which Barack Obama will govern?

The Illinois senator combined ambitious goals and a cautious temperament. He promised tax cuts, better healthcare, new energy programs and fiscal discipline all at the same time, and all without the bitterness and stalemate that arose when those issues were tackled in the past. Now, as Obama moves through his transition to the White House, this effort to square the political circle becomes the defining challenge in the months ahead. Which Barack Obama will dominate as he begins to govern? Too much of the ambitious liberal, and he rekindles partisan squabbles he was supposed to transcend.

Too much the cautious mediator who reaches across the aisle to compromise with Republicans, and he risks losing the energy and idealism that attracted millions to his candidacy.

The president-elect will have little undisturbed time as he works to strike the promised balance. The nation is in dire economic straits. His Democratic Party has been waiting since early in President Clinton's administration for a chance to work its will. And the conservative Republican opposition, though deeply wounded, is unlikely to roll over.

The new president will focus first on stabilizing the economy, Obama advisors and other senior Democrats say. He will seek early, high-profile legislative victories with bipartisan support. And he will probably defer some of his biggest, most controversial goals until later -- a decision that may send some of his liberal supporters into postelection depression.

"First you've got to deal with the economy," said Leon Panetta, a former chief of staff to Clinton who will advise Obama's transition team. "If you don't get that back on track, it undermines every other priority you want to achieve."

The current Congress may pass a new economic stimulus package by the end of the year. If it doesn't, that will almost certainly be Obama's first order of business.

Even if Congress does pass a stimulus, Obama will probably ask for more -- including some version of the middle-class tax cut he made a centerpiece of his campaign -- plus energy and infrastructure projects that would create jobs in a time of rising unemployment.