Yes they were, for different reasons. Ireland was still under England's thumb, and held down tighter than some of the other colonies, because of their proimitry and length of time since they'd been conquered, and because they, like the Italians and Mexcians, were Catholic.
Italy was culturally backward. Even today they have trouble holding a government together, (Which can be a "Good Thing", if one compares the current sitatuion to that during Mussolini's time). Criminals gangs ran rampant, especially in the south, many of those gangster "families" established themselves in the US.
The big, and most crucial difference is that the Mexicans are here illegally, while, for the most part, the others were legal immigrants, processed in by our Government, which sent many home as "undesirable", either criminal or sickly (at a time when the causes of disease were not as well understood, and cures almost nonexistent).
Actually out of the 20 million or so that came through Ellis Island only about 1%(240,000) were rejected.