...Condemnations of constitutional government have prompted dismayed opposition from liberal intellectuals and even some moderate-minded former officials. The campaign has also exhilarated leftist defenders of party orthodoxy, many of whom pointedly oppose the sort of market reforms that Mr. Xi and Prime Minister Li Keqiang have said are needed.

The consequent rifts are unusually open, and they could widen and bog down Mr. Xi, said Xiao Gongqin, a professor of history at Shanghai Normal University who is also a prominent proponent of gradual, party-guided reform.

“Now the leftists feel very excited and elated, while the liberals feel very discouraged and discontented,” said Professor Xiao, who said he was generally sympathetic to Mr. Xi’s aims. “The ramifications are very serious, because this seriously hurts the broad middle class and moderate reformers — entrepreneurs and intellectuals. It’s possible that this situation will get out of control, and that won’t help the political stability that the central leadership stresses.”...