In an article for Korach 5773, Rabbi Cherki notes that Korah's mistake involved confusing Samuel's temporary role with the ideal situation.
To disagree with Moses must be one of the most difficult things that a person can attempt. After all, his personality, which was greater than that of any other human being, shines out with power that it is certainly hard to resist.
In spite of the difficulty, Korah managed to do it. The Natziv explains that there were three components to the opposition to Moses, each of which would not have been able to wage the controversy alone.
The first figure in the dispute was a respected person, Korah, and it would have been expected to be beneath his status to openly oppose Moshe. Two others, Dathan and Abiram, had a reputation for bad deeds, and there was no way that alone they could have stood up to the leader of the generation. The third group, innocent men who wanted to get closer to G-d by bringing incense into the Holy of Holies, would certainly not have dared to rise up against Moses on their own.
The situation changed when the three elements joined forces. The respected figure (Korah) manipulates low-level but energetic activists (Dathan and Abiram), and they incite naive crowds (250 men). The result is a combination of the spiritual desires of the many, the jealousy of the activists, and the prominent leader's desire for honor.
However, this does not fully explain what happened. If the problem begins with a prominent man, there must be some spark of truth in his soul which provides a motive for the dispute. What was this holy intuition by Korah? "Korah was a wise man, what brought him to this foolishness?" [Bamidbar Rabba 18:8]. The foolishness is characterized by a lack of ability to discern between different levels of reality. As has been said, "For a drunkard the entire world appears to be a flat plain." The assumption that there is no difference between the Levites and the Priests, expressed in the cry, "All of them are holy" [Numbers 16:3], is rooted in the innate natural value of Yisrael, who are indeed "all holy."
It was necessary to find a practical example of this innate value, and what Korah saw was "that Samuel would descend from him" [Mechilta].
When Shiloh was destroyed, Samuel did not rush to build the Temple, even though David had prepared detailed plans for it. The Holy Ark was captured and it was not returned to a holy site. Samuel, the Levite, took on the role of High Priest! (Based on the Zohar.)
Samuel delayed in establishing the kingdom. And the Sanhedrin, the central institution whose task was to demand, "You shall rise up to the holy place" [Deuteronomy 17:8], was replaced by Samuel, who traveled from city to city within Israel. In practice, the approach of Korah – to abolish the national institutions - was instituted by his descendent! And this shows us the source of Korah's mistake.
The response to this approach is that the time of Moses was very different from the era of Samuel. A very unique situation developed in the time of Samuel. The priesthood was corrupt. The leadership of the nation was at fault in that it gave preference to the holy utensils over political independence and the lives of the Children of Israel. "And he said: Israel fled before the Philistines (a loss of independence) and there was also a great plague within the nation (the people of Israel were dying), and your two sons are dead (a personal tragedy)" [Samuel I 4:17]. All of this did not cause a great shock, but the verse continues, "And the Ark of G-d was taken. And when the Ark was mentioned, he fell backward from his chair." [4:18].
In this situation, when the value system was the opposite of what it should have been, it was necessary to temporarily suspend the attempts to reinstate the holy service and to establish the kingdom, and first of all to educate the people. The end result of this process was the establishment of the eternal kingdom of the House of David and the eternal Temple in Jerusalem. This is the opposite of Korah, who viewed the temporary situation as an ideal and the situation after the fact as the a priori preferred status.
Source: "AS SHABBAT APPROACHES" – a biweekly column in Shabbat B'Shabbato, Korach 5773, Volume 1477. (Zomet Institute) See: www.zomet.org.il/eng