President Trump released a $4.8 trillion budget proposal on Monday that includes a familiar list of deep cuts to student loan assistance, affordable housing efforts, food stamps and Medicaid, reflecting Mr. Trump’s election-year effort to continue shrinking the federal safety net.

President Trump on Monday sent Congress a $4.4 trillion budget with steep cuts in domestic programs and entitlements, including Medicare, and large increases for the military, envisioning deficits totaling at least $7.1 trillion over the next decade. The blueprint, which has little to no chance of being enacted as written, amounts to a vision statement by Mr. Trump, whose plan discards longtime  Republican orthodoxy about balancing the budget, instead embracing last year’s $1.5 trillion tax cut and new spending on a major infrastructure initiative.

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.

Congress has rejected President Trump’s plan to cut funds for biomedical research and would instead increase spending by the National Institutes of Health. The appropriations committees in both houses rejected Mr. Trump’s proposal to slash payments to universities for overhead — the “indirect costs” of research financed by the health institutes. These include the cost of utilities, internet service, data storage, the construction and upkeep of laboratories and compliance with federal rules protecting human subjects of clinical research.

President Trump’s proposal on Thursday for deep cuts to the budgets of a broad part of the federal bureaucracy was billed as a tough-minded and necessary corrective to the growth of the government’s power. But even  members of his own party questioned some of the cuts — and what was not being cut. “While we have a responsibility to reduce our federal deficit, I am disappointed that many of the reductions and eliminations proposed in the president’s skinny budget are draconian, careless and counterproductive,” said Representative Harold Rogers, Republican of Kentucky and a former chairman of the House Appropriations Committee.

The president’s plan would cut spending for many agencies to historically low levels. President Trump’s 2018 budget blueprint released on Thursday proposes cuts in discretionary spending for most government agencies to pay for large increases in military spending.