In the final days before the election, the US presidential race appears to be tightening again.

RACE TIGHTENS

Latest national polls continue to show Democrat Barack Obama leading Republican John McCain in the race for the White House.

However, the size of Obama's lead is shrinking a bit.

The Gallup daily presidential tracking poll of 2,789 registered voters taken Oct. 26-28 has two likely voter models.

One based on past voting behavior and current intention to vote shows Obama leading McCain 49 to 46 percent, while the second based on current intention to vote shows Obama up 51 to 44 percent.

The CNN survey shows that Obama is ahead 51 to 47 percent.

Among various polls, Obama's leading range is between 3 and 8 points, while the range was between 2 and 15 points Wednesday.

A new Ipsos/McClatchy Poll this week found McCain trailing nationally by 6 percentage points, 2 points closer than the week before.

The poll also found 8 percent of likely voters still undecided, enough to deliver the election to the Arizona senator if they moved to him as a bloc.

With Obama's lead seeming to be solid, many experts and a lot of media outlets are saying the race is effectively over.

However, some analysts pointed out that while he's still trailing, McCain still has a chance, although it looks very slim.

"Sure, McCain can win," election analyst Greg Mueller said. "It's not going to be easy. But it can be done."

Howard Fineman, a senior writer for Newsweek, said Obama's campaign staff believe it will remain a close race to the end because there is still a number of undecided voters who could vote for McCain on the final day.

GEARED UP FOR THE FINALE

Both campaigns are geared up for the finale.

Obama's campaign aired a 30-minute infomercial entitled "American Stories, American Solutions" Wednesday evening simultaneously on CBS, NBC, Fox, MSNBC, Univision, Black Entertainment Television, and TV One.

The ad was receiving very positive coverage Thursday.

The Politico called it a "smoothly produced infomercial" that "weaved together American iconography -- images of amber waves of grain, pickup trucks and American flags -- with portraits of iconic voters, testimonials from politicians and one business figure, footage of Obama speeches and direct appeals from the candidate."

The Los Angeles Times said the spot "offered even the swiftest channel-flipper the chance to see Obama looking presidential."

Meanwhile, McCain sharpened his attack on Obama, pointing out that Obama has broken a promise on campaign financing.

Addressing a Florida crowd Wednesday, McCain said, "When you're watching this gauzy, feel-good commercial, just remember that it was paid for with broken promises."

FOCUSING ON KEY STATES

As election day looms, both candidates have begun to focus on key states which will largely determine the outcome of the electoral college votes.

In this election, five states are considered crucial.

The Republicans haven't lost Virginia in 44 years and they absolutely need Florida to reach 270 electoral votes.

The Republicans never won the White House without carrying Ohio, and the last time Missouri backed a losing candidate was in 1956.

Though a traditional Democrat-leaning state, Pennsylvania is also pivotal because McCain does have a chance there.

On Wednesday, McCain toured Florida, trying to keep the state in the Republican column as some supporters worried about whether he can catch the better-funded Obama.

Obama arranged for a show of unity by appearing with former President Bill Clinton at a late-night rally outside Orlando, Florida, Wednesday.

Clinton hailed Obama, trying to inspire Democrats already smelling victory.

According to their schedules, Obama will hold rallies in Florida, Virginia and Missouri, while McCain will spend the whole day in Ohio.

MCCAIN STILL HAS A SHOT

For McCain to win, he must hold all the states that went for President George W. Bush four years ago, which would be enough to give him 286 electoral college votes and victory.

He could even lose one mid-sized Bush state, such as Virginia, which has 13 electoral votes, and still have more than the 270 Electoral College votes needed to win.

To be sure, that won't be easy. Obama leads in many of those states, including Florida and Ohio narrowly.

And McCain doesn't have any good prospects right now for offsetting the loss of a "red" state as he doesn't lead in a single state that went Democratic in 2004.

Dennis Goldford, a political scientist at Drake University in Iowa, said McCain still has a shot.

One way for McCain is to stay on the economic message, raising doubts about whether Obama's tax increases on the wealthy would hurt the economy while trying to convince voters that his own plan is better for growth.

Of course, another way that McCain could win is if the polls are wrong, particularly if there's a so-called "Bradley effect," in which white people are overstating their support for Obama, born to a black father and a white mother, to pollsters.