Our Gemara on Amud discusses some of the interchanges between Korach, Dasan and Aviram and Moshe.

Have you ever wondered why did Dasan and Aviram last so long? Typically, when Jews in the midbar sinned they would be met with swift justice, a plague from heaven or capital punishment for insurrection. Yet, Dasan and Aviram seem to act with impunity. First, they quarrel with each other and ignore Moshe’s rebuke (Shemos 2:13, Rashi Op. Cit and Nedarim 64b), snitch on Moshe (Midrash Tanchuma Shemos 10, Shemos Rabbah 1:31), then they stage a fake manna misinformation (Shemos Rabbah 1:29), and they were the first ones who also called early in the Exodus for turning back to Egypt (ibid, and Numbers 14:4). Yet, they only finally meet their fate as a result of the Korach rebellion. Why did it take so long?

Maharal (Gevuros Hashem 19) remarks on this and speaks of the necessity for good potential to always be balanced with evil potential. He says, Dasan and Aviram were the Anti-Moshe and Aharon. My father in law, Rabbi Michoel Miller Zichrono Livracha used to remark about the longevity of Dasan and Aviram. They were allowed to stick around because some of their skepticism regarding Moshe was healthy. Their challenges to Moshe’s leadership was part of a system of checks and balances that served a purpose — up to a point. Somehow, with the Korach rebellion, they crossed a line and whatever partial healthy motivations they had were eclipsed by plain jealousy and disrespect.