I think that one reason why the increase of anti- liberal solutions in the 19th Century differs from what was seen in the 20th Century is because of violence. There is a larger scale of death and political repression in the 20th Century than in the 19th Century "alternative vision." The rise of fascism in Europe was accompanied by the deaths of so many more than what could have been conceived in the 19th Century. Fourier, Marx, and Utopian critiques that were offered in the 19th Century was rooted more in theory than anything else. At the same time, these visions did not predicate themselves upon the mass level of death that was evident in the 20th Century.
The rise of charismatic leaders like Hitler and Stalin and the predisposition to use violence as a means of accomplishing one's political goals are the fundamental difference between the visions of both centuries. The use of political repression and eventual murder of individuals on such a large scale was never fully seen in the 19th Century. Such a condition was predicated as part of the rise to power in the 20th Century. There was a political aspiration and willingness to do whatever was necessary to achieve political power in the 20th Century vision that was not a part of the discourse in the 19th Century. This political aspiration resulted in a vast amount of death and suffering which makes it fundamentally different than anything articulated prior to it. While both visions sought to change what is into what can be, the presence of death and suffering in the 20th Century makes this rise in anti- liberal solutions fundamentally more dangerous than anything put forth in the 19th Century.