From Reason magazine, an interesting take on Barack Obama's liberalism:
That's one reason the liberal label may not be quite the ball and chain Republicans hope. If "liberal" is taken to connote gay marriage, socialized medicine, and unilateral disarmament, most people won't find it appealing. But Obama does not espouse those. If it is taken to mean trying something different from the last seven years—or offering a plausible alternative to war, inflation, and a housing bust—they will be receptive.
Back in 1980, everyone knew Ronald Reagan was too conservative to win. But when non-conservatives were presented with a conservative who was likable, temperate, and occasionally eloquent, many of them found they could vote for him. What Obama has going for him, more than anything, is a quality of calm and thoughtful gravity, which offers a refreshing contrast to President Bush's inarticulate defensiveness and McCain's stubborn pugnacity.
Most of the time, the candidate who sounds the most optimistic wins. People don't want to hear doom and gloom from their presidential candidates. The writer could have added that John McCain often sounds like a cranky old man and that Obama, despite running against an incumbent loathed by Democrats and graded poorly by most Americans (a perfect excuse to bitterly denounce Republicans, which Hillary Clinton gave in to more often than Obama), often comes across as the sunny one.