The Moses/Aaron party are in power and the opposition try with all the arguments and accusations they can summon to discredit them. “You made so many promises,” they say, “but the fact is that you have been a total failure, hanging on to leadership long after your use-by date”.
The weapons that the opposition uses are unfair. Korach and company fight dirty. They sound plausible; they cloak their venom in religious terms like tzitzit, mezuzot and Sifrei Torah; but no-one is fooled. This is no loyal opposition trying to prove themselves better statesmen, more attuned to what God and the people want.
No wonder that their own words turn against them; when they say, “We will not go up (to the Land)”, their punishment is to “go down” when the earth opens up as a chasm in front of them.