Bush benefits from high name recognition in primary polling. Despite being less well-known, Walker scores better grades because he has a higher ratio of people who know him giving him good grades.
Self-identified Republicans who are familiar with the candidates give Walker an average grade of B (2.75 GPA), while grading the potential of both retired neurosurgeon Ben Carson (2.62) and Florida Sen. Marco Rubio (2.48), just a notch lower at B-.
The next tier of candidates all receive a C+ average. That includes former Arkansas Gov. Mike Huckabee (2.32), Texas Sen. Ted Cruz (2.28), Jeb Bush (2.27), Kentucky Sen. Rand Paul (2.24), Ohio Gov. John Kasich (2.22) and former Texas Gov. Rick Perry (2.14).