Obama has no bus, the US goverment has two identical buses - one for the president, the other for the republican wannabe president.

The presidential bus is armored primarily to protect the president from tea party types who like to show up at town hall meetings with weapons and overwhelm speakers with their intelligence and logic - and their weapon display!

The republican bus is unarmored and the tires are bald. Presumably because the republic wannabe doesn’t have to be protected - except maybe from the liberals who can’t shoot anyway.