<p>As the fight for the Democratic presidential nomination begins in earnest, it's important for the candidates and Democratic voters to remember that the real prize is the White House, not the nomination.</p>
<p>So far, candidates have focused on winning the party faithful who vote in the early primaries and caucuses. That's understandable, but it's feeding a new conventional wisdom that all the candidates need to do to win is to turn out their base. That's a dangerous strategy for Democrats because the numbers just don't add up. About a third of all voters are Democrats. So even if every one of them marched to the polls, we'd still need a healthy slice of swing voters. To win next fall Democrats must persuade, not just energize. That's why Democrats need to make this election about the future. We must offer Americans a vision that tells them what we'll do for the country that George W. Bush won't. We can make a powerful case.</p>