Complex sentence: Because the series was so popular, however, it was often a subject for critical discussion and speculation-namely, that the series represented the struggle between the intelligentsia and the working class (with the Wolf representing the working class and the Hare the intelligentsia).
Split into simpler sentences: Because the series was so popular, however, it was often a subject for critical discussion. That they represented the struggle between the intelligentsia and the working class (with the Wolf representing the working class and the Hare the intelligentsia).