Some Republican lawmakers, especially those said to be considering presidential runs in 2024, have in recent months positioned themselves to pick up Mr. Trump’s baton in certain areas. Senator Marco Rubio of Florida and Mr. Hawley both came out in favor of sending $2,000 stimulus checks to Americans, and Mr. Rubio championed a program that disbursed more than $500 billion in forgivable loans to small businesses affected by the pandemic.

There is also a theoretical basis to the political shift. Even before the pandemic, many economists had begun to rethink their long-held view that large public deficits and debt would bog down the economy by pushing up borrowing costs for businesses and sending consumer prices soaring. A decade of relatively low interest rates and steady economic growth had prompted many economists to suggest that the United States could, indeed, afford to run a budget deficit.

The cost of debt “is substantially smaller than the current consensus,” Olivier Blanchard, a senior fellow at the Peterson Institute for International Economics and the former chief economist at the International Monetary Fund, said at a closely watched lecture in January 2019. “The implication of this is that in the future, we should probably revisit the fiscal rules that we are using.”