Possible Clues:

• Expression about the power of the rich
• "Wealth is power," or a hint to 16-, 22-, 38- and 51-Across
• "Wealth is power"
• 'Mere rhetoric is not enough'
• Proverb about wealth and power
• The rich have influence in economics lectures?
• "Cash makes things happen"
• 'Cash is king'
• And what it says about you is that you're rich?
• Being rich helps in conversations with bank manager