There have been no tax cuts

Kevin Williamson argues persuasively that the Reagan and Bush 'supply side' tax 'cuts' were nothing of the sort.  Instead they were simply tax deferrals - because spending was never reduced, they simply will lead to tax increases in the future on our children or an inflation which is just a regressive tax.  He does acknowledge the incentive effects of low marginal rates.  In the long run what matters is the productivity of the dollars spent:  if private spending yields returns in excess of the interest required to support the debt, then we get richer.  Likewise for public spending:  if we got a ten percent return on every incremental dollar spent by the government, then we should run huge deficits.  But private returns, while positive suffer from diminishing returns over time while public returns are almost always catastrophically negative.  This argues for low public spending but not for deficits.