WASHINGTON – It's hardly a secret that Barack Obama, like every president no doubt, muses about his ultimate legacy and spot in the presidential pantheon. He approaches his second term confronting tough and shifting challenges that will play big roles in shaping the rest of his presidency and his eventual place in history.

In the coming months, Obama will have to decide where to be ambitious, where to be cautious, and where to buy time.

He draws political strength from his surprisingly easy re-election in a bad economy. It's partly offset, however, by Republicans' continued control of the House, plus their filibuster powers in the Senate.