本句是并列句，前一个分句中，“if”引导条件状语从句，主句主语“it”指代“the tradition of ambition”。 后一个分句中“who”引导一个定语从句修饰“people”，“the educated not least among them”是“people”的补语。

If the tradition of ambition is to have vitality, it must be widely shared; and it especially must be highly regarded by people who are themselves admired, the educated not least among them。

youdao