The polls say that the presidential race in Pennsylvania has narrowed to a statistical tie over the weekend. But there are a million more registered Democrats in the state than Republicans. And the Obama campaign has 54 offices spread throughout the state ready to get as many Democrats as possible to the polls on election day.

But Romney has GOP voter enthusiasm working for him - as well as disillusionment in Obama that will probably depress the Democratic turnout.

The Morning Call of Lehigh Valley:

No one expects Obama to win Pennsylvania by the blowout 10-point margin he did in 2008, when he received 3.2 million votes to Republican John McCain's 2.6 million. Instead turnout is expected to be closer to 2000 or 2004, when the Democrat won by a percentage margin in the low single digits. Democrat John Kerry received 2.9 million votes in 2004, and Republican George W. Bush 2.7 million.

In 2008, Obama was a fresh face offering hope and change. Now a still-struggling economy and partisan vitriol have left many voters disillusioned.

Youth voters who came out in droves in 2008, for instance, are less engaged this time around.

To reverse a 24-year trend of presidential Democrats winning Pennsylvania, Romney needs to match or outperform Bush in the four Philadelphia suburban counties, all of which Bush lost except for Chester County in 2004.

Romney also needs high turnout on the western side of the state, where conservative, blue-collar, white voters make up much of the voting demographic. That was largely how Republican Pat Toomey narrowly beat Democrat Joe Sestak for the U.S. Senate seat in 2010.

Perhaps to Romney's benefit, one of the few hot races in Pennsylvania has been out west. The state's only real competitive U.S. House race is the 12^th District outside Pittsburgh. Western Pennsylvania also gets some bleed-over from the overwhelming attention both the Romney and Obama campaigns have paid Ohio.

Lara Brown, a political science professor at Villanova University, said there is a chance Romney squeaks out a 1- or 2-point win in Pennsylvania, provided certain geographic scenarios go his way. That narrow opening appears to be why the Romney team suddenly is investing time and money in Pennsylvania in the campaign's final days.

Jay Cost on the most likely victory scenario for Romney:

Not only have Democrats moved Philadelphia leftward, they have done an expert job of keeping turnout growing cycle after cycle. This is extremely impressive because, as a share of the state's population, Philadelphia County has been in a slow but steady decline (from upwards of 18 percent in the 1970s to about 12 percent today). What's more, the county is now just 45 percent white, and non-whites are less likely to vote than whites.

I cannot overstate this: The prowess of the Democratic operation in Philadelphia over the last decade alone is simply incredible. Even though the population has been flat since 2000, Barack Obama managed to net 130,000 more votes out of the county than Al Gore!

The problem for Democrats is that they will bump up against a ceiling, sooner or later: The party already regularly wins 80 percent or more of the county's vote, so there is not much room for growth there; additionally, the county's population is flat, so the vote margin is not going to increase merely because of demographics.

That's likely the context for Romney's entrance into Pennsylvania. The GOP campaign's strategy is probably three-fold:

1.) Extend the party's winning streak in Southwestern Pennsylvania. Win all the counties McCain carried with larger margins, and keep Allegheny County within 10 to 12 points.

2.) Mitigate the party's losses in the working class areas in the Northwest (Erie) and Northeast (Scranton, Wilkes-Barre, Allentown). The Democrats should win these areas, but the GOP's goal is to improve on Bush's 2004 standing.

3.) Drive up turnout in the exurban counties of Lancaster and York while mitigating losses in the interior suburban counties. In particular, improve on Bush's standing in Chester County and flip Bucks County from blue to red.

The stars are going to have to align exactly right for a Romney victory in Pennsylvania. But stranger things will probably happen tomorrow anyway so why not turning the Keystone State from blue to red?