Question: When did the Soviets hear Mikhail Gorbachev's proposition for "democratization"?
About the article "Dissolution of the Soviet Union", section "Soviet Union centre – one-party democracy".

Candidate passages:
As Brezhnev's health worsened during the late 1970s, the collective leadership became even more "collective".
Brezhnev's death did not alter the balance of power in any radical fashion, and Yuri Andropov and Konstantin Chernenko were obliged by protocol to rule the country in the very same fashion as Brezhnev.
When Mikhail Gorbachev was elected to the position of General Secretary in March 1985, some observers wondered if he could be the leader to overcome the restraints of the collective leadership.
Gorbachev's reform agenda had succeeded in altering the Soviet political system for good; however, this change made him some enemies.
Many of Gorbachev's closest allies disagreed with him on what reforms were needed, or how radical they should be.
The claim that the Secretariat was the Party's "center of power" was proven false in 1988 when it was shown that Yegor Ligachev chaired its meetings, rather than Gorbachev. 
Until the early 1980s, the United States had relied on the qualitative superiority of its weapons to essentially frighten the Soviets, but the gap had been narrowed.
Although the Soviet Union did not accelerate military spending after President Reagan's military buildup, their large military expenses, in combination with collectivized agriculture and inefficient planned manufacturing, were a heavy burden for the Soviet economy.
At the same time, Saudi Arabia increased oil production, which resulted in a drop of oil prices in 1985 to one-third of the previous level; oil was the main source of Soviet export revenues.
These factors gradually brought the Soviet economy to a stagnant state during Gorbachev's tenure.
Reagan recognized the change in the direction of the Soviet leadership with Mikhail Gorbachev, and shifted to diplomacy, with a view to encourage the Soviet leader to pursue substantial arms agreements.
Reagan's personal mission was to achieve "a world free of nuclear weapons", which he regarded as "totally irrational, totally inhumane, good for nothing but killing, possibly destructive of life on earth and civilization".
He was able to start discussions on nuclear disarmament with General Secretary Gorbachev.
Gorbachev and Reagan held four summit conferences between 1985 and 1988: the first in Geneva, Switzerland, the second in Reykjavík, Iceland, the third in Washington, D.C., and the fourth in Moscow.
Reagan believed that if he could persuade the Soviets to allow for more democracy and free speech, this would lead to reform and the end of Communism.
Speaking at the Berlin Wall on June 12, 1987, Reagan challenged Gorbachev to go further, saying:Prior to Gorbachev visiting Washington, D.C., for the third summit in 1987, the Soviet leader announced his intention to pursue significant arms agreements.
The timing of the announcement led Western diplomats to contend that Gorbachev was offering major concessions to the United States on the levels of conventional forces, nuclear weapons, and policy in Eastern Europe.
He and Reagan signed the Intermediate-Range Nuclear Forces (INF) Treaty at the White House, which eliminated an entire class of nuclear weapons.
The two leaders laid the framework for the Strategic Arms Reduction Treaty, or START I; Reagan insisted that the name of the treaty be changed from Strategic Arms Limitation Talks to Strategic Arms Reduction Talks.
When Reagan visited Moscow for the fourth summit in 1988, he was viewed as a celebrity by the Soviets.
A journalist asked the president if he still considered the Soviet Union the evil empire.
"No", he replied, "I was talking about another time, another era".
At Gorbachev's request, Reagan gave a speech on free markets at the Moscow State University.
In his autobiography, "An American Life", Reagan expressed his optimism about the new direction that they charted and his warm feelings for Gorbachev.
In November 1989, ten months after Reagan left office, the Berlin Wall was torn down, the Cold War was officially declared over at the Malta Summit on December 3, 1989, and two years later, the Soviet Union collapsed. 
After the deaths of three successive elderly Soviet leaders since 1982, the Soviet Politburo elected Gorbachev Communist Party General Secretary in March 1985, marking the rise of a new generation of leadership.
Under Gorbachev, relatively young reform-oriented technocrats, who had begun their careers in the heyday of "de-Stalinization" under reformist leader Nikita Khrushchev, rapidly consolidated power, providing new momentum for political and economic liberalization, and the impetus for cultivating warmer relations and trade with the West.
On the Western front, President Reagan's administration had taken a hard line against the Soviet Union.
Under the Reagan Doctrine, the Reagan administration began providing military support to anti-communist armed movements in Afghanistan, Angola, Nicaragua and elsewhere.
The Reagan administration also persuaded the Saudi Arabian oil companies to increase oil production.
This led to a three-times drop in the prices of oil, and oil was the main source of Soviet export revenues.
Following the USSR's previous large military buildup, President Reagan ordered an enormous peacetime defense buildup of the United States Military; the Soviets did not respond to this by building up their military because the military expenses, in combination with collectivized agriculture in the nation, and inefficient planned manufacturing, would cause a heavy burden for the Soviet economy.
It was already stagnant and in a poor state prior to the tenure of Mikhail Gorbachev who, despite significant attempts at reform, was unable to revitalise the economy.
In 1985, Reagan and Gorbachev held their first of four "summit" meetings, this one in Geneva, Switzerland.
After discussing policy, facts, etc., Reagan invited Gorbachev to go with him to a small house near the beach.
The two leaders spoke in that house well over their time limit, but came out with the news that they had planned two more (soon three more) summits.
The second summit took place the following year, in 1986 on October 11, in Reykjavík, Iceland.
The meeting was held to pursue discussions about scaling back their intermediate-range ballistic missile arsenals in Europe.
The talks came close to achieving an overall breakthrough on nuclear arms control, but ended in failure due to Reagan's proposed Strategic Defense Initiative and Gorbachev's proposed cancellation of it.
Nonetheless, cooperation continued to increase and, where it failed, Gorbachev reduced some strategic arms unilaterally.
Fundamental to the dissolution of the Soviet Union, the Gorbachev policy initiatives of Restructuring ("Perestroika") and Openness ("Glasnost") had ripple effects throughout the Soviet world, including eventually making it impossible to reassert central control over Warsaw Pact member states without resorting to military force.
On June 12, 1987, Reagan challenged Gorbachev to go further with his reforms and democratization by tearing down the Berlin Wall.
In a speech at the Brandenburg Gate next to the wall, Reagan stated:While the aging communist European leaders kept their states in the grip of "normalization", Gorbachev's reformist policies in the Soviet Union exposed how a once revolutionary Communist Party had become moribund at the very center of the system.
The growing public disapproval of the Soviet war in Afghanistan, and the socio-political effects of the Chernobyl accident in Ukraine increased public support for these policies.
By the spring of 1989, the USSR had not only experienced lively media debate, but had also held its first multi-candidate elections.
For the first time in recent history, the force of liberalization was spreading from West to East. 
Last of the Breed, a 1987 book by Louis L'Amour, tells the fictional story of Native American United States Air Force pilot Major Joseph Makatozi (Joe Mack), shot down by the Soviets over the ocean between Russia and Alaska and then captured.
Although the exact time is never stated, it appears to be the mid- to late 1980s as Mikhail Gorbachev's rise to power is mentioned.
It was L'Amour's second-to-last published novel. 
Soviet Union centre – one-party democracy.
At the 28–30 January 1987 Central Committee Plenum Mikhail Gorbachev suggested a new policy of 'democratization' throughout Soviet society.
Specifically he suggested that future Communist Party elections should offer a choice between multiple candidates, elected by secret ballot, however the CPSU delegates at the Plenum watered down Gorbachev's words and democratic choice within the Communist Party was never significantly implemented.
In addition Gorbachev radically expanded the scope of Glasnost stating that no subject was off limits for open discussion within the media, although the cautious intelligensia took almost a year to begin pushing the boundaries to see if he meant what he said.
For the first time, the Communist Party leader, speaking at the Plenum of the Central Committee, appealed over the heads of its members for the people's support in exchange for a dramatic expansion of liberties.
The tactic proved successful in that within two years political reform was invulnerable to the party 'conservatives', the unintended consequence was that having saved reform, the January 1987 choice, ultimately killed the very system it was designed to save.
On 7 February 1987 dozens of political prisoners were freed in the first group release since the Khrushchev years in the 1950s.
On May 6, 1987 Pamyat, a Russian Nationalist group, held an unsanctioned demonstration in Moscow.
The authorities not only did not break up the demonstration by force—but later, the police kept traffic out of the demonstrators' way while they marched to an impromptu meeting with Boris Yeltsin, head of the Moscow Communist Party, and at that time one of Mikhail Gorbachev's closest allies in the ruling Politburo.
On July 25, 1987 a group of 300 Crimean Tatars, calling for the right to return to the Crimean homeland from which they were deported in 1944, staged a noisy demonstration for several hours near the Kremlin Wall as dozens of police and soldiers looked on.
On 10 September 1987, after a lecture from hard-liner Yegor Ligachev at the Politburo for allowing two small unsanctioned demonstrations on Moscow streets, Boris Yeltsin wrote a letter of resignation to Gorbachev who was holidaying on the Black Sea.
When Gorbachev received the letter he was stunned – nobody in Soviet history had voluntarily resigned from the ranks of the Politburo.
At the October 27, 1987 plenary meeting of the Central Committee of the CPSU, Yeltsin, frustrated that Gorbachev had not addressed any of the issues outlined in his resignation letter asked to speak.
He expressed his discontent with both the slow pace of reform in society, the servility shown to the General Secretary, and opposition to him from Ligachev making his position untenable, before requesting to resign from the Politburo.
This was sensational.
Besides the fact that nobody had ever quit the Politburo, no one in the party had ever had the audacity to address a leader of the party in such a manner in front of the Central Committee since Leon Trotsky in the 1920s.
In his reply, Gorbachev accused Yeltsin of "political immaturity" and "absolute irresponsibility".
Nobody in the Central Committee backed Yeltsin.
Within days news of Yeltsin's actions leaked and rumours of his 'secret speech' at the Central Committee spread throughout Moscow.
Soon fabricated "samizdat" versions began to circulate.
This was the beginning of Yeltsin's re-branding as a rebel and he continued to grow in popularity as an anti-establishment figure.
The next four years of political struggle between Yeltsin and Gorbachev was a major factor in the destruction of the Soviet Union.
On November 11, 1987 Yeltsin was fired from the post of First Secretary of the Moscow Communist Party.