Problem with that is, politicians promise all kinds of things for their election campaigns, then do whatever TF they want anyway once they're elected and sitting pretty effectively untouchable by the peasantry that elected them, getting rich and fat for a few years before "retiring" to a cushy board position of some company they "incidentally" helped during their political "career".
Politicians are mostly professional parasites and most political systems seem to attract, apart from the odd once-in-a-while genuine idealist, exactly that type of people.