OF the many experiments in democracy launched in recent years, none is more difficult than Haiti's. That island nation has never experienced democracy in its 200 years of independence, and it has rarely had anything approaching orderly government. But Haiti is now trying to turn that history around. So far the results are, at the least, better than might have been expected. Since the United States engineered the return of President Jean-Bertrand Aristide a year ago, the country has been relatively stable. People can walk the streets in safety; normal commerce is possible. Haiti's nascent electoral processes were sorely tested last June. Aristide backers swept most parliamentary races, but the balloting was marred by widespread irregularities. Many opposition parties chose to boycott the run-offs, which were held last Sunday. Voter turnout was very low this second time around. A presidential election is scheduled for December, which will provide yet another major test of the political machinery. While blatant fraud appears to have been largely weeded out, the commission charged with running elections is still sputtering. Some fast repairs are needed. In fact, every facet of reform in Haiti has had to be super-fast - from electoral procedures to reconstituting the police. The critical deadline is only a few months away: The UN presence, dominated by Americans, will end in March. Mr. Aristide has promised to step down just before that, as his successor is inaugurated in accord with the country's new Constitution. But as leader of the dominant party, Aristide will still exercise power and influence. And, we hope, his American allies will still be on hand to aid the rebuilding process. That process, after all, has just begun.