The latest Rasmussen poll taken in Pennsylvania shows what most of us who are following polls and the state of race rather closely already knew: John McCain is surging in Pennsylvania.

According to the Rasmussen poll, McCain is now only 4% behind Barack Obama. Earlier this week, the gap was 8%.

Obama has made life difficult on himself in this blue state by making remarks earlier this year many Pennsylvanians found insulting – “clinging to guns and religion” – and did not agree with – “spreading the wealth around is good for everybody.”

Additionally, Obama’s life has been made more difficult by Rep. Jack Murtha’s statement recently that Pennsylvanians would not vote for Obama because they are “racist.” He later clarified those remarks by saying he did not mean to call them “racist” but “redneck” and implying they were less developed than Americans living in other parts of the country.

Not only did Obama’s lead go down from 7 to 4 points in just a week time, Obama was leading by 13%earlier this month. Suddenly it becomes very, very clear why McCain and Sarah Palin are campaigning as aggressively as they are in the state that was once Benjamin Franklin’s home.

One of the main reasons for Obama’s slip is that Pennsylvania Democrats are no longer supporting him as massively as they once did. A few weeks ago, 86% of them planned to vote for Obama. Today, that figure has fallen to 75%, which is a low number for a nominee of a party.

Important for McCain is that his favorable ratings are slightly higher than Obama’s: 55% vs. 54%. For now, the only problem is that 51% of Pennsylvania voters trust Obama more when it comes to the economy, against 46% who say the same about McCain. If he wants to win the state, McCain will have to convince Pennsylvanians that Obama is worse than he is on this subject.

Still, even if McCain would win Pennsylvania, he would have a hard time winning the election as a whole, simply because there are only a few states remaining that he can potentially win. He will need to win Pennsylvania, virtually every other key battleground state remaining, and then one extra state in which he has to surprise the world.

Not impossible, certainly unlikely. Despite what happens in Pennsylvania.