Hey, remember when I predicted that Democrats would be invincible?

Now don’t judge me by the cover alone. I made the argument that every growing demographic in this country—nonwhite voters, younger people—is trending Democratic. It’s a ticking time bomb for the GOP. That’s why I felt safe in saying that “Republicans have no hope of making serious inroads into Democratic advantages in 2010 or likely 2012 or 2014 and so on.” And just for kicks, I told the Republicans to get a better prescription-drug policy because “they’re gonna need a lot more Prozac.”

So why did the Dems wind up depressed after losing the House? The problem is a bad economy dampened turnout among key Democratic groups in a non-presidential year. But the enthusiasm will bounce back when Obama’s on the ballot again.

Punditry is like weather forecasting; the winds can shift without warning. I remember when nobody would bet a McDonald’s Quarter Pounder that Bill Clinton would win the White House. So it’s easy to blow a big one.