With the examples of Hong Kong and Istanbul perhaps on their minds, Mr. Putin and his cronies surely remember how, 30 years ago, Mikhail Gorbachev experimented with a limited free election. Previous Soviet national and regional elections had been shams, with Communist Party candidates invariably winning their posts because they faced no competitors.

Mr. Gorbachev wanted to invigorate the Soviet system by making it more competitive and allowing some nonparty members into its legislative body.

To do so, he created a new legislative body: the Congress of People’s Deputies, consisting of 2,250 delegates. One-third of the seats were reserved for Communist Party members, leaving the other two-thirds open to contest. Of course, even in the openly elected seats, the party-endorsed candidates had numerous advantages. And yet, when the election took place in March 1989, there were big surprises: 300 candidates, or about 16 percent of the new legislative body, had defeated party-endorsed candidates. Among those who lost were five Central Committee members, one member of the Politburo, and 35 regional party bosses.

Mr. Gorbachev touted the new election as a victory for his reforms and a successful effort to democratize the Soviet political system. The hard-liners, unnerved by new freedoms and unaccustomed to any political opposition, were not amused then, as they are not amused now.

One longtime Kremlin insider and an architect of Mr. Putin’s regime, Vladislav Surkov, recently declared that Russia could be maintained only as a military-police state, and that Mr. Putin was the only leader whom the Russian people could trust. Putinism, he maintained, was a new political system, and like Marxism or Leninism, would last for centuries.

Despite such wishful thinking — or posturing — at the top, Putinism has been steadily falling apart: Government-controlled media are struggling to sustain the president’s falling ratings; Russia’s regions are impoverished; the oil- and gas-dependent economy is anemic; Russia’s elites are consumed by infighting for pieces of a shrinking pie; and the young generation is less susceptible than their forebears to government propaganda.

Putinism appears destined to last a far shorter time than either Marxism or Leninism. It was conceived as a hybrid autocracy in which a ruling elite controls most of the economy and media in the name of the state, but tolerates a limited number of independent but closely watched businesses and media outlets. Unlike the Chinese Communist Party, with its total control of society, Mr. Putin’s Kremlin has chosen to leave an escape valve for dissenting opinions — as long as they remain marginal and pose no threat to those in power.