Democracy is following people's will, not "making things equal". In a democracy, the people have the power to decide and anyone has the power to elect, be elected and to voice his opinion freely.
His point is that democratic systems are subverted if absolute equality is not enforced. It’s a crude argument but basically correct. The only way you prevent usurpation is by making sure one individual doesn’t have any obvious means of scaling his influence to the point that he can challenge the democratic militia.
Then again, outsized influence is a problem in democracies as well; this is what creates the conditions for a Caesar figure to emerge in the first place.