Mao Tse-tung was a real-life political leader during the Cultural Revolution in China. We don't actually get to meet him in the book (otherwise we'd be the happiest person in the world, at least according to Ji-li), but we hear a lot about the guy.
Even though she's not comfortable with bad-mouthing a teacher, and Ji-li doesn't really get all of the new rules, she still follows Mao and everything the guy preaches. Listen to what she tells us about him:
His brilliant eyes were looking into the distance as if he were already thinking about the great revolutionary task that lay ahead of him. I could not look at the painting without feeling inspired. I was ready to follow him anywhere. (7.3)
Describing Mao, Ji-li reveals to us how persuasive and dynamic the leader is. She would follow him anywhere, and so would pretty much anyone else. After all, dude's super powerful plus he has bold new ideas for the country that promise greater equality. Thing is, while Ji-li idolizes Mao, she doesn't have a clear picture of who the guy really is—it's not until many years later that Ji-li realizes her belief in Mao was the result of brainwashing.
See? We told you the guy was convincing.