Pennsylvania joins Missouri as a late addition to the website’s list of undecided states in the upcoming general election.
In three recent polls, President Barack Obama’s once-large lead over Mitt Romney fell in the past week in the Keystone State, which has 20 electoral votes.
Romney and GOP supporters have spent very little money so far in Pennsylvania, but that could all change if the presidential contest is indeed close in the state.
The windfall could also benefit Tom Smith, a little-known GOP Senate candidate who is rising in some polls in his race against Senator Bob Casey.
One poll from the Siena College Research Institute puts the race at 43-40 percent for President Obama in Pennsylvania. Two other polls, which have GOP connections, put Obama’s lead at 5 points and 2 points.
Siena is also known for its historical polls that rank U.S. presidents.
All three polls were taken after the first presidential debate.
“With a month and two more debates to go, Pennsylvania’s direction on the road to the White House remains in doubt. The final tally depends upon the sizable group of voters that in early October had yet to decide. With clear differences in the presidential race by party and area, turnout will make the difference,” said Siena’s Don Levy.
Polls taken by other groups before the debate put Obama’s lead over Romney at between 7 and 12 percent in Pennsylvania.
A GOP presidential candidate hasn’t taken Pennsylvania since 1988, when George H.W. Bush defeated Michael Dukakis.
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But the balance of power in Pennsylvania has shifted away from the Democratic stronghold of Philadelphia in recent years.
In 2008, Terry Madonna and Michael Young from Franklin & Marshall College described how President Bush was able to defeat his Democratic foe 20 years earlier.
“The key to Bush's 1988 victory was holding onto the Philadelphia suburbs while losing only two counties, Lackawanna and Philadelphia, east of the Susquehanna (River),” they said, adding that demographic changes since then make a lower Democratic turnout in Philadelphia another key factor.
Hillary Clinton was able to execute a similar strategy in 2008 when she defeated Barack Obama in the Democratic primary that year by nine points by appealing to "Casey Democrats" in the western part of the state, who voted for the late Governor Robert Casey.
Scott Bomboy is the editor-in-chief of the National Constitution Center.