Argentina’s libertarian President Javier Milei won decisive victories in key districts in midterm elections Sunday, clinching a crucial vote of confidence that strengthens his ability to carry out his radical free-market experiment with billions of dollars in backing from the Trump administration.

In the election widely seen as a referendum on Milei's past two years in office, his upstart La Libertad Avanza party scored over 40% ​​of votes compared with 31% for the left-leaning populist opposition movement, known as Peronism, exceeding analysts' projections.

Milei, a key ideological ally of U.S. President Donald Trump, said his party and allied blocs picked up 14 seats in the Senate and 64 in the lower house of Congress on Sunday, bolstering the government's support in the legislature enough to uphold presidential vetoes and block impeachment efforts.

At La Libertad Avanza headquarters late Sunday in downtown Buenos Aires, a beaming Milei hailed the election sweep as a mandate to press forward with his spending cuts and introduce ambitious tax and labor reforms. The results also automatically position him as a candidate for reelection in 2027.

Perhaps never has an Argentine legislative election generated so much interest in Washington and Wall Street.

Trump appeared to condition a $20 billion currency swap deal with Argentina's central bank and an additional $20 billion loan from private banks on a good showing for Milei in national midterms, threatening to rescind the assistance for the cash-strapped country in the event of a Peronist victory.

This added to mounting pressure on Milei, who has scrambled to avert a currency crisis since the Peronist opposition won a landslide victory in Buenos Aires provincial polls last month. Argentina’s bonds and currency nosedived as markets sensed that the public was losing patience with Milei’s reforms and that the midterm race would be tight.

To stem the run on the peso, Milei burned through billions of dollars in foreign exchange reserves to shore up the peso. In an extraordinary move, the U.S. Treasury then came to the rescue, selling dollars to help meet soaring demand for greenbacks and finalizing the credit line.

In the end, the Peronist alliance performed poorly, underscoring how weak the once-dominant movement has become in the Milei era.

Trump, while on his way to Japan on Monday, posted on Truth Social that Milei was “doing a wonderful job” after his party beat expectations in midterm elections.

The results showed Milei’s young libertarian party gaining support across the country — including in some surprising corners that have long been under the sway of Peronism.

Despite Milei’s new momentum, experts caution that the irascible president still needs to court political allies to see through his agenda. Given the limited number of seats up for grabs in this election, it was mathematically impossible for Milei to secure a majority in either house.

Seeking to capitalize quickly on Sunday’s results, Milei said he called the country’s powerful provincial governors to accelerate agreements on long-term economic reform.

The electorate appears increasingly polarized between beneficiaries of Milei's reforms and those who say they're struggling to make ends meet like never before.

AP Video by Victor R. Caivano