As with most "revolutions," the Risorgimento was elitist/intellectual in origin, and manipulated by another elite that was able to mobilize and control sufficient popular support to benefit from it all.
If there was a military elite, it was led by the royal House of Savoy. Garibaldi was the romantic revolutionary, typical of the time....(think Lajos Kossuth in Hungary). As with others, Garibaldi was useful to Count Cavour as a propaganda factor. Neither Cavour nor the Sardinian kingdom was about to lose control of the Risorgimento to a populist such as Garibaldi, and he never commanded forces sufficient to make any difference.
Mazzini always seemed to me the effete intellectual who was unable to accomodate politics. He refused to take the assembly seat to which he had been elected (1865 or 66?), because of the oath of allegience to the kingdom. Therefore he had no real influence in political life, and remained an outsider, divorced from what was happening in the 1860s and 70s....not only in Italy but in Germany and Britain as well.
Mazzini was something of a quasi-Marxist, but that dog didn't hunt very well in western Europe after 1848/49. The whole Marxist specter became nothing but a bogey after the disastrous 1871 Commune in Paris. By that time, people were weary of the recent conflicts, and there was no real support for any wide socialist upheaval. Socialists became, unlike Mazzini, politicians involved in established political institutions.