Bring in "new" states
He has a great chance of winning away from the Republicans the states of Virginia, Missouri, Iowa, Colorado, Nevada, New Mexico, possibly North Carolina and Florida too. He currently maintains a slim lead in Pennsylvania and Ohio, obviously crucial states...
Michigan will be solidly Democratic this fall...
He could possibly do it but he has a challenge in that he will have to put together his electoral majority in a way no Democrat has done in a long time. The battleground states are where it is decided.
Here'a a great site showing electoral maps all the way back to 1789!