If all around braking performance is poor, which of the following could be a potential cause?

When considering the potential causes of poor all-around braking performance, a clogged compressor air filter can significantly impair the function of the brake system, particularly in air brake systems. The air compressor supplies the necessary compressed air needed for the braking system to operate effectively. If the air filter is clogged, it restricts airflow to the compressor, resulting in insufficient air pressure. This can lead to longer stopping distances and compromised brake responsiveness, contributing to an overall decline in braking performance.

Worn brake pads can also cause braking issues but are more directly linked to specific brake fade or noise, rather than an overall systemic issue affecting all braking performance. Excessive tire pressure does affect ride quality and tire wear, but its impact on braking would generally be secondary to the direct limitations on brake function caused by air supply issues. Poor alignment can lead to uneven tire wear and handling problems, which affects steering and stability, but does not directly result in diminished brake performance.

Therefore, a clogged compressor air filter is a critical factor that can lead to an overall poor braking performance due to its effect on the air supply critical for the operation of air brakes.