Update: The final Susquehanna Polling & Research Poll shows a 47-47% tie heading into the Tuesday election. Romney is seen slightly more favorable (+4) than Obama (+1). Adding to Romney’s advantage is that an overwhelming 71% place economic and fiscal issues as their top concern, and 56% believe the nation is headed on the wrong track. Romney campaigns in Pennsylvania Sunday afternoon.

Original: Mitt Romney and Republican allies have suddenly poured more than $10million into Pennsylvania to fund a late push by the presidential challenger. Two weeks ago, a poll by Susquehanna Polling and Research showed Mitt Romneyleading Barack Obama by four points in the Keystone State, 49-45%. (Note: a previous edition of this article incorrectly stated that the 49-45% Romney lead was this week’s poll).

In what could prove to be a brilliant campaign move, the Romney campaign hid details of a Sunday campaign appearance in Pennsylvania until after the Obama team released their final campaign schedule.  Critics have been dismissing Susquehanna’s tight polling for over a month based on little more than the fact that a Republican presidential candidate hasn’t won Pennsylvania since the 1980s. George W. Bush came close, however, in both of his campaigns. Republicans also took the US Senate seat and Governor’s mansion in 2010, despite Pat Toomey being called “unelectable” by the media.

If Romney wins Pennsylvania, the race is over. If the Obama campaign and the media ignore Susquehanna’s polling, they do so at their peril. Let’s take a quick look at the three most recent major statewide races in Pennsylvania, and how Susquehanna fared compared to their polling counterparts:

2010 US Senate Race – Susquehanna was the only pollster to nail Pat Toomey’s two-point margin of victory over Joe Sestak. The media-despised Rasmussen Reports was second closest (two points off), while Quinnipiac and Public Policy Polling (the “real” pollsters) were off by three points.

2010 PA Governor’s Race – Republican Tom Corbett won the race by eight points, 54-46. Susquehanna polled the race within one point, showing Corbett winning by seven points. Rasmussen, PPP, and Quinnipiac reported the same margin, resulting in a four-way tie in correctly predicting the race.

2008 Presidential Contest – For those shocked at seeing Obama trailing Mitt Romney by four points in the latest Pennsylvania poll, the same polling outfit had Obama defeating McCain by 8 points four years ago. Obama won by 10. Although their final poll was done two weeks before election day, they actually polled within two points of the final results, along with PPP, Quinnipiac, and Survey USA. The results were closer than other state polls done by Rasmussen, ARG, Marist, and Morning Call.

In the last three statewide contests, Susquehanna had an average margin of error from the actual result of one point, making them Pennsylvania’s most accurate pollster. Romney winning Pennsylvania doesn’t seem out of reach at all. Obama won the state by 10 points in 2008, a smaller margin than he won by in Wisconsin and Nevada, which are now toss-ups. He won by about the same margin in New Hampshire, Iowa, Minnesota, and Colorado in 2008 as well; all of those states are now in play. Romney is also benefiting from a lack of early voting in Pennsylvania, depriving union goons the opportunity to drag voters to the polls for weeks before the election.

While the left called Romney’s move into Pennsylvania “desperate,” it could prove brilliant. If Romney wins Pennsylvania, as Susquehanna suggests he is on the verge of doing, he no longer needs Ohio, Wisconsin, Nevada, Iowa, or New Hampshire. Of course, if he does win Pennsylvania, he stands to win some of those states, too. At this point, Romney isn’t just looking for a win. He is looking for a mandate.

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