The Dem Horse Race by the Numbers

As always, take these figures with a grain of salt:

National, per Gallup:
Obama - 52
Clinton - 43
*Dates conducted: April 4-6. Error margin: +/-3%

Pennsylvania, per Quinnipiac:
Clinton - 50
Obama - 44
*Dates conducted: April 3-6. Error margin: +/-2.7%

North Carolina, per Rasmussen:
Obama - 56
Clinton - 33
*Dates conducted: April 3. Error margin: +/-4%