How do we know that a certain development is the beginning of something evil? We need to foresee the end, but can we? Perhaps things change by themselves and all plays out well. But what if not?
And if we are sure the end will be evil, how can we avoid that? Who exactly is "we", whom can we trust (with our political opinion) and how can "we" stop evil?

Some people realize sooner, some later and some never that they (we) are a part of something evil. Events on a global scale are similar to some on individual level. For example, violent relationship does not start over night but step by step; there are red flags down the road but for different reasons people overlook them; and one day you end up with a blue eye, another with broken arm etc. Autocratic leaders and govs are like violent partner in this relationship. Recognition and understanding this red flags and dynamic and reacting adequately and in time is a way out. Now, when you multiply individual factors with amount of people involved in the dynamic, equation is set; then just needs to be solved :D.
WE are a group of people who investigate and contemplate given info, regardless of personal characteristics, except that distrust is in common. If we are to react in time, so much more people have to be prepared for reaction; given that most people realize late, too late or never, the question is how minority can make the change, that is, what are the means to fight much powerful enemy; same Q that you asked.
Imo A is that connection is the key; this means that without trusts in each other and feeling of togetherness anything can hardly be achieved. About choosing who to trust, maybe those who showed with their actions what they are standing for; words make too much fog and gaslighting. People are too alienated and to afraid; not only that we don.t trust our govs but also each other. Divide et impera. So, the humanity is doomed :)
We cannot stop evil but we can make it lesser... I hope.