The incumbent has been bedeviled by challenges that would have rattled any government. But Mr. Macri, 60, was particularly vulnerable after assembling a cabinet heavy on academics and private-sector experts, but without “good mid-management officials who understood how to run the state,” said Ernesto Calvo, an Argentine political science professor at the University of Maryland.

That led to mistakes, critics say, including an early decision to issue billions in debt in foreign currency. The move left the government with little flexibility when confronted by shocks like a devastating drought last year or a rise in the United States interest rate that made Argentina less attractive to investors.

With the Argentine central bank hemorrhaging, Mr. Macri last year turned to the International Monetary Fund for a $57 billion line of credit, a politically toxic move in a country where many blame the I.M.F. for a devastating 2001 economic crisis.

While that lifeline gave the president some initial breathing room, the economy has continued to flail.

“Macri in 2015 was seen as a structural change — the first sign that the region was moving away from leftist populism — and this was going to represent a change not only for Argentina but for the region as a whole,” said Jimena Blanco, head of the Americas research team at Verisk Maplecroft, a risk consultancy. “Now Argentina’s failure is seen as a cautionary tale.”

Mr. Macri, a former businessman who served two terms as mayor of Buenos Aires, had tried to transform the country into a regional powerhouse that would rely on market forces to attract investment and expand the middle class.