By Chris May

PHILADELPHIA (CBS) — The 2012 Democratic National Convention begins today, and there’s no question the Democrats have their work cut out for them.

The polls may not reflect it yet, but the Republicans had a strong week in Tampa. A week in which they hammered home the theme of a failed presidency while establishing their nominee as a viable alternative. Maybe Mitt Romney’s speech Thursday night didn’t blow you away, but for millions of Americans who were paying attention to him for the first time — and not seeing him in a quick news report or an attack ad — he came across as serious and credible. He passed the “can-I-see-this-guy-as-president” test. And that makes him considerably more dangerous to President Obama.

So what can the Dems do to stop the momentum?

We’ve been on the ground in Charlotte for about 24 hours, and it’s been fascinating to hear a couple of refrains over and over. First, there is the endless talk about the middle class. Every statement, every policy position seems to come back to the middle class. It’s a disciplined, focused effort, and it sounds great on TV.

Second, taking on the question: Are people better off than they were four years ago?

It’s not an easy question for President Obama’s supporters. Unemployment has been above 8% nationwide for 43 consecutive months. The debt is nearing $16 trillion. Those are big numbers that people notice. But the push back we’re hearing is that the country IS better off than it was four years ago, because four years ago we were losing hundreds of thousands of jobs each month. Today, there’s job growth. Modest job growth, to be sure, but growth nonetheless. Supporters argue that we’re moving in a positive direction. They are embracing the question and arguing that things are better now and will get even better during a second Obama term.

I heard Sen. Tom Carper speak to the Delaware delegation today, and he delivered that message in a speech that was as sunny and optimistic as any I’ve heard in a long time. If Democrats can capture that spirit and project it from the stage in Charlotte, they may just regain their footing and win a second term for President Obama.