IT would be hard to find a political spectrum anywhere in the world broader than the Congress of People's Deputies that opens in Moscow today. Conservative Marxists who believe in a tightly disciplined one-party state will rub shoulders with socialist reformers who make the Eurocommunists of the 1970s look tame, Christians who want to see the protection of the traditional Russian way of life, and open supporters of a multiparty system and a mixed economy.
A few years ago, many of the 2,250 new deputies would probably have been arrested for expressing the views they put in their campaign platforms. And some, including human rights activist Andrei Sakharov, have been imprisoned or exiled for their opinions.
The Congress is perhaps Soviet leader Mikhail Gorbachev's biggest political gamble yet.
His tactics are as usual brilliant, but even he is in danger of being outpaced by the fast-moving political situation that he himself has created.
The first task of the new congress will be to elect a president and a standing parliament, the Supreme Soviet, of about 542 members. As of yesterday afternoon, they had not decided either on an agenda for the first day, or on how the Supreme Soviet would be chosen.
He first broached the idea of a parliament with real powers - and himself as president - just under a year ago at the 19th party conference.
His main aim seems to have been to escape from the constraints of collegial rule by the Politburo, the Communist Party's inner leadership. Most Politburo members advocate a more gradual and less dramatic approach to change.
They are supported in this by large segments of the Communist Party apparatus, and particularly by many regional Communist Party leaders who realize, correctly, that the reforms spell the end of the political system that created them.
Reformers say that valuable time has been lost brokering compromises with the party leadership.
Gorbachev wants to move faster than the ruling Politburo. One of the most perceptive Soviet political analysts, Igor Klyamkin, sees the Congress as a ``blocking mechanism'' that will fend off conservative resistance to reform, while at the same time carrying through fundamental political and economic changes.
If reform is to work, he says, the Congress will have to become a ``second center of power that is stronger than the present party structure.''
But in the Congress, Gorbachev runs the risk of facing an even more unruly and willful collection of people.
One major wild card has already emerged: Moscow maverick Boris Yeltsin.
Many deputies with political ideas much more radical than Mr. Yeltsin's seem for the time being to have rallied behind Gorbachev: The menacingly conservative tone of speeches at a plenary session of the Central Committee four weeks ago seems to have shaken them.
But their own radical ideas still keep protruding.
``You can't reform something that doesn't exist,'' insists Viktor Kiselyov, a representative of one of the more outspoken Moscow deputies, Oleg Bogomolov. ``You have to start all over again and create a new political structure.''
The new structure will have to redefine the role of the Communist Party, he says. The party will have to cease to be ``above the law, above everything.''
At the moment, he says, the party is trying to draw new deputies ``into their influence loop - it's what Adam Michnik [a political adviser to Poland's Solidarity] calls the counter-reformation.'' But, he implies, they are not succeeding.
The biggest immediate problem for Gorbachev will probably be Yeltsin, who in the last few days has abandoned all pretense of deference toward the Soviet leader.
On Monday the Communist Party Central Committee voted to recommend Gorbachev as their choice for the presidency. Yeltsin abstained.
On Tuesday evening he announced his resignation as minister in the state construction bureau.
``He doesn't have to worry about a job, he is going to be president,'' his aide Lev Shemayev told the Monitor yesterday. Yeltsin will be nominated from the floor of the Congress today, according to Shemayev.
Yeltsin seems to want a complete turnover of the political leadership.
At Monday's Central Committee meeting Yeltsin called for an immediate party congress, and the replacement of the Politburo and Central Committee, Mr. Shemayev says. The next party congress is not due until 1991.
But Yeltsin's support among so-called radical reformers may no longer be as solid as it was a few weeks ago. Some are beginning to be haunted by the nightmare that Yeltsin, whose basic political reflexes seem more authoritarian than libertarian, might join the Communist Party apparatus in an alliance against Gorbachev.
In addition, the approximately 150 members of parliament from the Baltic republics are unlikely to back Yeltsin for president.
``I would react to his candidacy with extreme caution,'' says Mariu Lauristin, of the Estonian delegation.
Many of the ideas that deputies have on their personal agenda would have been unthinkable in the very recent past.
Some, like Vitaly Korotich, editor of the weekly Ogonyok, have called for commissions to oversee defense policy and the state security committee (KGB).
Baltic representatives, along with the more radical deputies from other parts of the Soviet Union, want curbs on the use of the armed forces in demonstrations. They are also demanding the repeal of other decree laws they feel are repressive.