First, a little background:
The Democratic Relative Edge in Presidential Elections Pennsylvania since 1972:
1972: +2% 1976: +1% 1980: +2% 1984: +7% 1988: +3% 1992: +4% 1996: +2% 2000: +4% 2004: +5% 2008: +3%
And with this information at his fingertips, on the howling steppe north of Silvergrad, Romanian General Jay Cost orders his troops to throw away their weapons, point their fingers at Reality, and make "Pow! Pow!" noises.
He is astonished when it has no effect:
Jay Cost: Morning Jay: Mitt’s Pennsylvania Push: Real or Fake? | The Weekly Standard: So why head into Pennsylvania, a state the GOP has not won in twenty years?
Liberal proponents of the “emerging Democratic majority” love to talk about shifting demographics in their favor, but they regularly ignore the many ways in which demographics have shifted toward the GOP. For instance, Nevada and its six electoral votes tipping red to blue is all the rage, but West Virginia and its five, Kentucky and its eight, Arkansas and its five, and Missouri and its ten switching blue to red is ignored.
And so it goes with Pennsylvania, a state that has slowly been shifting toward the Republicans for the last twenty years…
Only at the Weekly Standard would a state that has been a constant +3% for Democrats for a generation be called a state that "has slowly been shifting toward the Republicans".
Making a stab at Pennsylvania would be a good strategy for Ryan-Romney only if there were some indication that something had eroded that 3% edge this year. But relative to the three most likely swing states--OH, CO, VA--Obama-Biden is up in Pennsylvania this year by an additional 2.5%, 4.0%, and 4.3%.
Nate Silver's state relative swings: