Republican Keynesianism isn't new, either -- much of the supply-sider argument (especially as formulated by Laffer in the Reagan era) is fundamentally Keynesian

Republican Keynesianism isn't new, either -- much of the supply-sider argument (especially as formulated by Laffer in the Reagan era) is fundamentally Keynesian. Politicians of both sides run into an incentive problem when implementing Keynesian policy because it requires what commentators denigrate as "austerity" in good times in addition to heavy recession spending. There's every incentive for politicians to keep the spending up in good times, and little (other than ideology or commitment to good governance, neither of which have proven especially important to most political actors) incentive in the other direction.