Former Soviet leader Mikhail Gorbachev declared today that he will run for the Russian presidency, insisting he could win as the leader of a democratic coalition despite polls indicating he is deeply unpopular.

Having toyed publicly with the idea of a comeback since at least mid-1993, Gorbachev's announcement today was no surprise.

Perhaps mindful of Gorbachev's popularity ratings of less than 1 percent in the polls, Izvestia, the capital's leading newspaper, ignored the announcement altogether. Tonight's evening news broadcasts gave it short shrift, mentioning it after items on the fighting in Chechnya, the first anniversary of the assassination of a popular television personality, a special report on life in the southern region of Kabardino-Balkaria and the doings of President Boris Yeltsin, the man who eclipsed Gorbachev in 1991.

Gorbachev was named Soviet leader in 1985 and brought unprecedented changes to the Communist-ruled nation through his policies of glasnost (openness) and perestroika (restructuring). The effects of his reforms were limited, however, by his dedication to preserving communism. After surviving an abortive coup by hard-liners in 1991, he reluctantly presided over the breakup of the Soviet Union at the end of that year.

In a news conference, Gorbachev, who will celebrate his 65th birthday Saturday, bitterly dismissed his low public standing, asserting, as he has in the past, that it is part of a government-controlled plot. His real support, he says, is far greater.

He called on all democratic forces in Russia to unite in a broad coalition, declared himself ready to lead it and warned of the consequences of a "false choice" between Yeltsin's government and the Communist Party, both of which he lavished with criticism.

"What they are offering is not a democratic future for Russia," he said. "That is why we must unite."

Asked if he plans to run even if no such coalition responds to his call, Gorbachev replied, "Yes, I will."

He then said he was not formally declaring his candidacy for president, even though he had already said that "in my heart I am prepared for that."

It appeared highly unlikely that any prominent politician would join Gorbachev in a coalition, much less one that the former Soviet president would lead. Gorbachev said Grigory Yavlinsky, a reformist economist who is running for president, might be a potential ally. But a spokesman for Yavlinsky mentioned Gorbachev's poll ratings and dismissed his coalition proposal as "not very realistic."

For years, virtually since he was expelled from his Kremlin office in December 1991 by Yeltsin, Gorbachev has waged a twilight struggle against obscurity at home while basking in adulation abroad. With each of Yeltsin's missteps, Gorbachev blasted his former arch-rival in interviews from the spacious offices of the Gorbachev Foundation, his private think tank. But he was accorded little attention.

Still vigorous, self-confident and much healthier than Yeltsin, Gorbachev can barely contain his frustration at having been sidelined in a society that is rapidly changing.

He has struggled to comprehend the depth of his unpopularity at home, where some people, especially the elderly, blame him for the collapse of their beloved Soviet Union while others remember him as a voluble, slightly creaky old-timer who never really gave up on communism.

"He is a person who has an old mind and an old mentality," said Vladimir Fomichev, 65, a factory worker. "I don't think he fits in this new democratic society. As president he was unpredictable and indecisive and he wasn't able to pursue a policy of democratic transformation." Said Yuri Kuznetsov, 30, a computer engineer: "He was a windbag and a miserable president."

That sentiment was reflected in the news conference today, in which Gorbachev was asked about some of his Soviet government's failings -- to block unified Germany's entrance into NATO and to provide immediate, accurate warnings to residents around the Chernobyl nuclear reactor in Ukraine when it malfunctioned in 1986 in the world's worst nuclear accident.

"It's an enormously human story," said Stephen Cohen, a Princeton University historian who has written extensively, and sympathetically, on Gorbachev.

"This is a man who feels that he was cheated by history, that he is the father of Russian democracy, the father of Russian reforms and that he can set reforms on a course where they would be stable. . . .

"Here's a man who's already a historical figure entering a campaign. How many historical figures are walking around asking for votes? You just don't see things like this." CAPTION: Mikhail Gorbachev urges Russian democrats to unite behind his candidacy.