Who may primary Obama?

[RIP Robert H Bork]

Unless Obama has some sort of crippling incident between now and 2012 (stock collapse, terrorist attack, major scandal, etc.) there will be no serious primary challengers.  It'll all be jokes like Kucinich.

Kucinch might not want to run. If he's seen as ignoring his district on some hopeless race again, he'll have his own primary to worry about again.

This. I remember reading about Kucinich barely getting 50% in his Congressional primary in 2008, and dropping below 60% in the general election. He may think again about running in 2012, especially since it is an incumbent President that he would be running against.

[RIP Robert H Bork]

The position of Kucinich will be interesting in 2012. There will be a new map and much of his district will go to augment Fudge's black-majority district. Cuyahoga will not have enough population for two whole districts so the part left over from Fudge's district will either have to combine with Lorain or Medina to form a district.

If Kucinich wishes to remain in Congress, he may need more time to campaign in a new district, and would not be able to take the time away for a presidential run. If the district puts him in competition with another incumbent Democrat, he may just decide that a presidential run is the only way to go.

I think it would. The 10th district, which Kucinich represents, is surrounded almost entirely by the 11th and 13th districts (and it narrowly borders the 14th). I think that he will most likely gain some land from the 13th district, which is also Democratic.