The goal of the police is to have secure jobs with a decent salary and benefits, and ideally be meaningful in some way (could be promoting public safety... could be exerting power over others).

Often enforcing the law helps secure budgets (especially when it comes to enforcing drug laws with lucrative civil forfeiture seizures), but more recently many police departments have tried a different tactic when budgets have been threatened: actively refusing to enforce the law, in order to increase crime and prompt political change.