Mr. Xi’s record so far — unyielding opposition to political liberalization and public protests has been a hallmark of his rule — has suggested a politician who abhors making concessions. He has fashioned himself into a strongman unseen in China since the days of Deng Xiaoping and Mao Zedong, and few if any party insiders and political analysts expect him to give serious consideration to the demands for full democratic elections in Hong Kong.

In fact, his strongman style may have helped create the crisis.

The protesters are demanding open elections for Hong Kong’s leader, the chief executive. China has agreed to allow the position to be elected by popular vote starting in 2017.

But China’s rubber-stamp Legislature last month rejected any change in election rules that would open the race to candidates not vetted by a committee that is reliably pro-Beijing. And while there still may have been room for compromise, Mr. Xi met with business leaders from Hong Kong in a closed-door session in Beijing last week to reiterate that the party will not allow political change in Hong Kong, the former British colony of 7.2 million people.

“If he had negotiated from a position of strength,” Mr. Diamond said, “and pursued a strategy of delivering ‘gradual and orderly progress’ toward democracy in Hong Kong, albeit at a more incremental timetable than democrats were hoping for, he could have pre-empted this storm.”

Instead, there are signs that Beijing may only harden its position. On Monday evening, a commentary on the website of People’s Daily, the party’s main newspaper, claimed the upheavals in Hong Kong were instigated by democratic radicals who had sought support from “anti-China forces” in Britain and the United States and had sought lessons from independent activists in Taiwan. It called them a “gang of people whose hearts belong to colonial rule and who are besotted with ‘Western democracy.’ ”