Left-leaning economists hate the timing and the composition. But the expansionary fiscal policy they sought is on the way. The fiscal austerity that drove the budget deficit from around 9 percent of G.D.P. in 2010 to 3 percent in 2016 has, for practical purposes, been abandoned. First, Republicans passed a $1.5 trillion tax bill in December that sharply cut rates on businesses. Then last week they made a deal to undo budget caps demanded by the Republican House in 2011. President Trump signed that bill on Friday.