Here are three things that have happened so far in 2019.

The former chief economist of the International Monetary Fund, Olivier Blanchard, argued in a speech that for countries like the United States, high public debt isn’t necessarily a problem. To people who follow the I.M.F., it was as if a former pope came out with an endorsement of the devil.

Alexandria Ocasio-Cortez, the charismatic new congresswoman who has shown an uncanny ability to drive public policy debates, indicated openness to “modern monetary theory,” the idea that public spending need not be constrained by tax revenues.

President Trump delivered an 82-minute-long State of the Union speech in which he did not use the words “debt” or “budget deficit.”

Economic orthodoxy that ruled for decades held that fiscal responsibility was inherently good and the national debt a leviathan to fear. Now the intellectual and political currents are flowing — gushing, really — in the opposite direction.

After President Trump’s election, Republicans decided to pursue their agenda of tax cuts and higher military spending without doing the unpopular work of paying for it.

Democrats are coming to believe they have hamstrung themselves in pursuit of their goals by worrying about so-called pay-fors, policies that offset the cost. When they next take power, they may feel empowered to take on a much more ambitious, expensive agenda.

And macroeconomists are confronting the reality that the sky did not fall, even as the United States swung from a $236 billion surplus in the 2000 fiscal year to a $779 billion deficit in 2018. By their old theories, high deficits and debt should have caused interest rates and inflation to rise, and government borrowing should have “crowded out” capital from the private sector.