It's inevitable given the political structure. Since votes are distributed by area and population rather than by wealth, wealthier political divisions will necessarily bribe poorer ones into political compromises that are closer to the wealthier divisions' preferences than they would have been without bribery. The only way to prevent that would be for the overall polity to have much lower taxes and thus much less money to divert to interdivisional bribery. (In many polities, this would be very much against the preferences of the wealthier divisions, so this "solution" is never seriously contemplated.)

Of course, TFA describes a different way to come to substantially the same result. Tokyo still makes the important decisions.