The Previous Rebbe related that when the Tzemach Tzedek attended the government-backed Jewish education conference in Russia’s capital Petersburg, he confronted the government representatives and their lackeys to the point that his freedom and even his life were threatened. He was asked how he could endanger his life when thousands of Jews were looking to him for spiritual and physical guidance. He answered that his sons could take over, and if not, the unity of the Chassidim would stand for them and carry them until the arrival of Moshiach.
Now, our Rebbe says, we find ourselves over 100 [now over 150] years after the passing of the Tzemach Tzedek. His sons we don’t have, but the Chassidim are unified and prevail over all difficulties, breaking through the dark exile and enabling the revelation of “then Hashem [Havayeh] will be the light of the world.” This unity nullifies all bad decrees and destroys all barriers.
[Motzei Shabbos Tzav 5726]