As much as people may be willing to mimic the behavior and appearance of others in order to fit in, secretly they often envy those who show intentional dissent. According to many researchers people admire the person who has the guts to do what they do not – challenge group norms – as long as the person is not challenging their own norms.
“Indeed, people may speak up and dissent from important group norms not because they want to be difficult and destructive, but because they care for the group and its future.” 
The heroes of novels are often principled rebels, not lacking in loyalty but willing to speak up against those with power for the benefit of the group. In the world of fiction the group is eventually swayed by stirring words from this altruistic rebel. But in real life? If you want to craft a story with a true uphill struggle you should look at studies on how the minority voice of dissent is able to influence the majority. Group dynamics affect the challenge of being a real-life rebel with a cause.
In social reality groups tend to seek a consensus (i.e. get everybody to go along) if the opinions of the majority are not rooted in reality. In this case the uniformity in opinions serves the purpose of validating ideas that really cannot be validated. If a group member questions the idea or backs someone who does they run the risk of being excluded. 
If rebels wish to sway others to follow their cause they must learn the importance of consistency (It is not necessarily the hobgoblin of small minds). Majorities start with the assumption that the minority is not correct but the persistence on the part of the minority creates a complexity. ‘How can they be so sure and yet so wrong’?  If the minority view is going to have any chance of gaining a following the supporters must remain consistent over time and behave consistently with one another. If this sticking to their guns is seen as attention seeking, or a rigid belief rather than consistency, it will fail to gather support.
Also the rebel with a cause does not have the luxury of both ‘winning friends’ and ‘influencing people.’ If the rebels remains adamant in their position they may influence others, but most people will not like them. Those that persist in their minority views, are often punished by the powers that be in a group. However, if the proponents of the minority view attempt to gain power through appeasing others in the group, they are seen as giving in, and lose any chance to influence others. 
The uniformity of the majority is often not as solid as it seems. People will appear to adopt the majority position but privately disagree with it. On the other hand the dissenter must convert others to the minority position. People can be influenced privately, but this private change will eventually have to stand up under scrutiny.
But most importantly when a rebel speaks up they must do so before members of the group have a chance to follow through with the action that the rebel disagrees with. When a person complies with group demands before the rebel speaks up, they often view the rebel’s disagreement as a personal rejection. They tend to preemptively reject the rebel even if in agreement with the principle that caused the defiance in the first place.
Those in the group that have yet to show an opinion by acting in conformity with the majority are those most willing to admire the person who dissented for principled reasons. When the defiant persons voices an opinion that is not held by the majority, these people often feel liberated and believe that, by following the rebel they have done the right thing .