While there are indeed many sorts of Argentine "nationalism", the one that prevailed from 1930 till well advance the XX century was the one that was formed in the 1920ies, and was the one that could be carachterized as militaristic, pro-Hispanic, ultra-Catholic, anti-liberal, anti-Communist, anti-American, anti-British (to a much lesser extent, though) and not very fond of parliamentary democracy. At first these nationalists were agrarian, and thought Argentina could (and shold) live forever exporting beef and wheat produced in large "estancias". It was only in the late 30ies/early 40ies that some nationalist became promoters of industrialization.
This form of nationalism was never widespread in society as a whole, which was far more secular and cosmopolitan. These nationalist never won an election on their own, for example. Perón considered them "piantavotos" (that is, if you had one of them in a formula, you'd get less votes, and may even loose the election).
But they were quite influet¿ntial among the army, and since the army meddled a lot with politics, they ended up being a force to considered.
Before 1920, the rich in Argentine were pro British and pro French. They tended to be secular, and saw Spain as a backward nation. They also tended to desdain colonial history, and see it as a reason for our relative backwardness.
However, when an electoral reform bill was passed in 1912, which allowed for free elections nationwide for the first time, these aristocrats couldn't organise themselves in a party, and loss the election in face to the Radical Party (a middle class party). Some of the members of the upper class, unable to get to office democraticaly (unlike, for example, their counterparts in Chile, which had a powerful Conservative Party) became dissapointed with democracy as a wole. They began seeing it as something alien to our culture and "Latin", traditions, and became admirers of Primo de rivera in Spain and Mussolini in Italy (with some reservations in these case, given his relations with the Church).
The election of Yrigoyen in 1928 and the effects of the 1929 crisis gave this minority faction the excuse to stage a succesfull coup in 1930, inaugurating a series o military interventions in politics which weren't good at all. And though they lasted in power less than two years, and they fail to reform the Constitution according to their corporativists ideas, the damage was done.
What if a different form of national had prevailed, one more of the "American" or even "French" sort? That is, one that wasn't so attached to a single religion and to our colonial past, and one who had put the Constitution as one of values of the Motherland? Would it have been possible to do so? I think it could have been: after all,for example, in the 1920ies you could have Jews in a relatively high possition in the army, something which became impossible after 1930 for quite a while (after that year, they could be successfull in every other sector of society, even in politics, but not in the army).
So, what if a more inclussive, less attached to tradition and democratic form of nationalism had prevailed in the army? Something more akin to nowadays patriotism?