Barack Obama's victory is proof of a fundamental realignment in American politics, said John Judis in The New Republic online. So the president-elect should ignore the advice to "go slow." If Obama and the Democrats who now dominate Congress "act boldly," they can arrest the economic downturn by spending big on infrastructure and by adopting national health insurance. That will have the added benefit of laying "the basis for an enduring majority."

Obama's first big test will be resisting the temptation to overreach, said Ruth Marcus in The Washington Post. After spending eight years in the wilderness, "the leftward precincts of his party are not inclined toward either compromise or patience." But Obama will have greater success over the long haul if he avoids the early defeats that robbed Bill Clinton of momentum as a new president when he skewed too far to the left.

There's every reason to expect Democrats to "stream into Washington and dive into the federal treasury" with giddy abandon, said Jonah Goldberg in the New York Post. That would be bad for the country, but good for Republicans. Unless Obama sticks to his promises, "mostly implied," of centrism and moderation, voters will fire Democrats in 2010 the way they just fired Republicans.

Reality will be enough to keep Democratic power in check, said Dick Morris and Eileen McGann, also in the New York Post. Obama will take office with a clear mandate, but "as the economy falters, he'll find himself unable to raise taxes as he wants and stymied in his plans for government takeover."