IN appraising today's fascinating political developments in the Soviet Union, it is worth remembering that the two-party system was a late, not an original, feature of American democracy. When George Washington, Thomas Jefferson, Samuel Adams, and the other Founding Fathers were writing the Constitution, they did not intend a political system based on two rival political parties. Nor were they united in believing in democracy.
They founded a republican form of government based on limited franchise. The only voters at the beginning were male, heads of families, property owners. The founders provided for representative government. But it was not democratic and, at the beginning, did not include what we now call political pluralism.
The essence of the system as it exists today is its pluralism. In the US and in all true ``democracies'' there are two or more political parties, and it is possible for the electorate to throw one party out of office and vote in a different party, and do it without bloodshed.
In the Soviet Union today there is one political party, Communist. It enjoys a monopoly on political power. From Joseph Stalin down through Leonid Brezhnev it was monolithic and controlled from the top. Policy was not made in the local or regional branches. It was made at the top and imposed by diktat on all party members below.
This is no longer entirely true. Of all the changes Mikhail Gorbachev is making in the USSR (which he sometimes refers to as Russia), perhaps the most important of all is that he is creating an opposition in the form of a split in the Communist Party.
Ronald Reagan was scarcely out of the Kremlin when Mr. Gorbachev was visibly busy stacking the lists of delegates for the big June 28 party conference with people of his choosing. And his primary opponent, Yegor Ligachev, was just as busy also trying to stack the deck with his people.
Mr. Gorbachev insists that no one is going to be fired. That remains to be seen. And it also remains to be seen which of the two - Gorbachev or Mr. Ligachev - is being more skillful at packing the list of delegates to the conference. But beyond doubt there are now two factions in the Soviet Communist Party. Each has a recognized and visible leader. The rival leaders remain in the Politburo. The issue between them is the pace and extent of perestroika, or restructuring.
No one can know how this will come out. The issue can make or break the economic and political future of the USSR. It is apparently going to be settled by votes in the conference. There has never been anything like this in Moscow since Stalin imposed the monolithic one-party system on Russia.
If Gorbachev wins out in the voting, then his country will be on the way toward not only economic renewal. It will also have taken its first footstep down the road toward a two-party system.
The logical progression from what has happened so far would seem to be the development of rival branches of the Communist Party - one wishing to press forward down the perestroika road, the other wanting to put on the brakes and pull back before factories are liquidated for incompetence and workers can be fired for loafing on the job.
If this issue can be settled by vote in a party conference without bloodshed and without political purges, then the step will have been similar to the one the US took when it settled the issue of redemption of the almost worthless currency that had been issued during the period of the wartime Continental Congress. It ``wasn't worth a continental'' until Alexander Hamilton won out over Thomas Jefferson.
That issue split the Founding Fathers into Federalist and anti-Federalist parties. These evolved into Whigs and Republicans, who in turn evolved into the present system. But it took most of a century for a difference over repudiation or redemption of the old wartime currency to turn into two, highly organized Republican and Democratic Parties. Americans need not expect open, avowed, and structured political pluralism to emerge quickly in the Russia of Mikhail Gorbachev.
The important thing is that the Russians have taken a first step that is visible to the public eye. Everyone in Russia knows that there is rivalry at the top, two factions, and a vote coming up in the party conference, which begins June 28. It may be more important in history than Mr. Reagan's first trip to the once ``evil empire.''