Obama losing by 4 in an internal Democratic poll probably means he is losing by than that in reality. Indiana should swing back to the GOP this time barring a massive landslide nationally.
Indiana is not a sure thing for Republicans. Take a good look at the December approval rating (42-55) from an internal Republican pollster... that is before a recent surge in national approval ratings for the President. It's probably in the 46-48% area of approval which means that the state is in range of a D hold for President.
Indiana remains significantly more R than the US at large, so its 11 electoral votes will account for something between the 350th and 390th electoral votes for the President if he gets that many. 2008 is not a one-time fluke for President Obama; the state is drifting D.
I'm not sure what you mean by a "massive landslide nationally". Is it like Obama 2008 or FDR 1944? Or is it like Eisenhower 1956? The ceiling for a Democratic win of Indiana is very low. Indiana was in play throughout 2008 even when the nationwide election looked close; Obama won it by a small margin.