By Yael T. Abouhalkah, Kansas City Editorial Page columnist

Why polls matter: All of a sudden, John McCain has cut into Barack Obama's lead among likely voters. Obama is down to a 49-47 percent margin in Tuesday's Gallup Poll. And Obama has more troubles.

The sudden plunge on the likely voter poll pulls him below the winning 50 percent mark for the first time in more than a week.

In other words, even as Democrats become more confident of victory on Nov. 4, the polls are showing McCain pulling closer to his own victory.

What's that mean for McCain?

On Tuesday, he stayed on message, telling voters that he and Sarah Palin actually can win despite what the polls say today.

"It's wonderful to fool the pundits because we're going to win the state of Pennsylvania," McCain said in that state, where he's trailing Obama.

And if the polls suddenly start showing that McCain is staying closer to Obama these last few days, that could re-energize Republicans to come to the polls to vote for the GOP standard bearer.

Any good news for Obama? Yes.

He had a similar, small lead among likely voters in mid-October, but lengthened it to as high as 51-44 percent just four days ago.

Now Obama and his supporters have to hope he can rebound in the polls again and grab a lead that holds through Election Day.