The basic contours of the 2016 presidential race have been fairly obvious for months: to win, Donald Trump will need to hold onto the "red" states that backed Mitt Romney over President Obama four years ago, while flipping several "blue" states. The former won't be easy, with Hillary Clinton focusing resources in states like North Carolina and Arizona.And the latter is likely to be even harder. While a handful of states Obama carried appear likely to shift this year -- Iowa tops the list -- Trump faces a tough challenge finding the necessary number of electoral votes.That's where Pennsylvania comes into play. With 20 electoral votes, the Keystone State could go a long way towards handing the presidency to Trump -- a point that's not lost on the Republican campaign. The Washington Post reported over the weekend that Trump's aides are increasingly focused on Pennsylvania, and Melania Trump will deliver remarks on Thursday in suburban Pennsylvania -- her "first appearance on the campaign trail since her speech at the Republican National Convention."It led the New York Times' Nate Cohn to raise a good question:
"For the third straight election, we're going to spend the last week talking about a last-ditch GOP effort in [Pennsylvania], aren't we?"
Yes, actually, we are -- and if we look back a little further, it's not just three cycles.In early November 2012, Mitt Romney and Paul Ryan made "a late advertising and in-person push" in Pennsylvania, "parachuting into the Keystone State ... for last-minute visits with scant days left to go in the race." Obama nevertheless won the state in results that largely mirrored the national popular vote, 52% to 47%.In late October 2008, Pennsylvania became "the only blue state on the board" that John McCain's campaign was "serious about trying to win." He nevertheless lost Pennsylvania by 10 points.In late October 2004, George W. Bush made quite a few campaign appearances in Pennsylvania, including one last stop on Nov. 1, the day before Election Day. John Kerry carried the state anyway by about 2.5 points.In 2000, Republicans went all out to win Pennsylvania, including choosing Philadelphia to host the party's national convention, but Al Gore nevertheless carried the state by about 4 points.In 1996, Bob Dole made frequent appearances in Pennsylvania before eventually giving up on the state -- he lost by nearly 10 points -- and in 1992, then-President George H.W. Bush made a late appearance in the Keystone State, declaring a week before the election, "Something is happening here." In a way, something did happen: Bush lost by 9 points.Taken together, a pattern starts to emerge. Yes, H.W, Bush carried Pennsylvania in 1988, but no Republican has replicated the feat since. In nearly every cycle, the GOP ticket believes this is the year Pennsylvania turns "red," and makes a last-ditch effort to make that happen, only to discover soon after that their efforts were for naught.That's not to say a Trump victory in Pennsylvania is impossible, but with his campaign making one last push into the state, it's hard not to get the feeling we've seen this movie before -- and we know how it ends. The latest polling puts Hillary Clinton's lead in the state at around 6 points.