If I understand your question correctly, yes.
A revolution could occur and the revolutionaries could win and form a government subscribing to their ideals. However, if the ideals of the revolution are largely betrayed or exist in name only and/or the government is performing objectively bad actions, the revolution can be "cancelled".
If just the latter occurs, the ideals themselves may, or are likely, still perfectly valid, but people may have a more negative perception of them.
That's part of it and that's a great answer, but I was also thinking of legit and good revolutions. Like the media apparatus is so strong. Bernard was not a revolutionary by any stretch of imagination, but he did get somewhat tarnished by accusations of sexism and such. Wondering if that has become a way to neutralize "subversives" too at this point.
I think you see that with the idea that a lot of people on the left are just white males and not much else (even though this is false and it is very diverse). The powers that be will try to paint a movement, or what have you, that goes against their interests as being dominated by privleged people and/or people from a historically dominant group or having some type of bigotry and/or reactionary views, especially if there basically nothing else to legitimately criticize them on.
As you mentioned, there was the idea that Bernie Sanders, as ran to be President, was some sort of sexist, even though his record and stated positions do not support. A lot of the people who said it either knew they were making a proverbial mountain out of a molehill or are the type of people who think the slightest opposition to a woman (such as competing against one in an election or just disagreeing with) is sexism in and of itself.
The point is there are almost no ideological issues on which the left (including the alt-right) are actually justified in adopting “some type of bigotry” of the idiotic “leftist bigotry” accusation. Yes, not everything that the alt-right is peddling are good ideas (there are plenty of good ideas that they are selling as being stupid), but they are trying to break up a system that is giving away everyone’s money to the richest of the rich and stifling everyone else and denying people a chance to have a better life