In essence, the theory of supply-side economics is based on three main premises. First, cutting income taxes, particularly for high-wealth individuals, frees up their income to "trickle down" and benefit virtually everyone, because the wealthy will use their tax relief to create faster job growth. This enhanced job growth will trigger rapid economic expansion and, hence, create growing wages for most.
Indeed, according to the theory, the growth in jobs and personal income for the majority of workers will be so great that even though the taxes of top earners are being cut, overall tax revenue will be undiminished.
What's scary is that this theory has been law since 1981 and continues to enjoy broad support, despite no evidence that it works.