Between 1860 and 1930, exploitation of the rich land of the pampas strongly pushed economic growth.[3] During the first three decades of the 20th century, Argentina outgrew Canada and Australia in population, total income, and per capita income.[3] By 1913, Argentina was among the world's 10th wealthiest states per capita.[4]
And then of course beginning in 1945 the ratlines assured the freedom of many nazi war criminals in Argentina. There are plenty of reasons for Trump to like Argentina during the first half of the 20th century.