It no longer sucks it up and blows it out the top. The auger is turning. Any ideas?

Is the impeller that pushes the snow up and out the shoot, turning?

Hi,
Your manual is available online and it contains the parts breakdown. According to the breakdown, a spring pin connects the impeller to the gearbox shaft. Suggest you check it. Manual is available here by clicking the word Download:
http://www.searspartsdirect.com/partsdirect/part-model/Craftsman-Parts/Snow-removal-equipment-Parts/user-manuals/manual-downloads/Model-536887251/0247/1507200?modelNumber=536887251&diagramPageId=&documentId=
Peace,
Clarke

Harold, yes the impeller turns as well as the auger.

Clarke, I see the spring pin in the diagram. Do I need to remove the access cover on the bottom of the snowblower in order to see if it is intact? Or is the fact that the impeller turns enough to say it is intact?

Hi,
I would make sure that the impeller is actually fastened to the gearbox shaft and not turning by friction. Holding the impeller blade and turning the engine over with it turned off(by the manual starter) and seeing if the impeller can be held back should do it.
For access I believe I would probably access it from the top by removal of the chute.
Peace,
Clarke