I'm not sure it could exist coherently, at least not in any place with multiparty democracy.
It can exist in single party states (or similar) because the one thing that would unite all dissenters is the demand to have a means to reject the establishment. Once that exists, there's nothing uniting the different anti-establishment forces so they'll fragment into smaller coalitions based on where they agree.
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The Party told you to reject the evidence of your eyes and ears. It was their final, most essential command.
If you're not careful, the newspapers will have you hating the people who are being oppressed, and loving the people who are doing the oppressing. —Malcolm X
Just a reminder: under international law, an occupying power has no right of self-defense, and those who are occupied have the right and duty to liberate themselves by any means possible.