Honesty is so much a matter of social stigma that it takes phenomenal gumption to face up to the societal, and even familial, ridicule that a simple "I won't bribe" statement will get you. A significant reason that honesty doesn't do too well is that its benefits don't get as much positive PR as those of corruption do.
In such a scenario, the vision of clean politics is mostly left to the fantasy of singularly brave idealists who won't buckle under the derision.
Laughable as it may seem, it is probably even better that it is left to the CM's son.