MAKING GOOD on a grim threat, Sikh gunmen assassinated the mainstream Sikh politician who had, bravely, signed a historic agreement in July with Indian Prime Minister Rajiv Gandhi to bring a meas strife-torn Sikh-majority state of Punjab. Harchand Singh Longowal had gone on to consent to an Indian government decision to hold early elections in the Punjab, which has been under central rule for nearly two years. The killers wished to discredit Sikh moderates, who almost certainly speak for most people in their community, and to scuttle the July accord, which they denounce as a "sellout."

But the extremists seem to have underestimated the people they mean to terrorize. After Mr. Longowal's killing, Prime Minister Gandhi was given a fistful of reasons why he should put off the September elections. He rejected them all, understanding that to delay would let the terrorists claim they had blocked the return of normal popular rule in the Punjab and that they had cowed the partners of the July agreement. On its part, Mr. Longowal's Akali Dal party reaffirmed the agreement with the central government and threw itself into preparations for the elections.

The coming elections (to local office and to the federal parliament), if they are actually held, will do more than restore democracy to a beleaguered state -- though this is no small feat in a place that has seen as much bloodshed as has the Punjab.

Both of the principal parties contending -- Mr. Gandhi's national Congress (I), which has many Sikh members in the Punjab, and the largely local Sikh Akali Dal -- are committed to the July agreement. But the turnout will constitute a referendum on it, and the voters will be saying which party they prefer to guide the Punjab in the new process. It speaks well for Mr. Gandhi's attachment to the constitution, by the way, that he has passed up an opportunity to extend presidential rule in the Punjab and has instead chosen to return democracy and to put his own party's primacy in the state on the line.

None of the Indians taking part in this effort to end the terror, the sectarian violence and the threat of secession in the Punjab can have any illusions left about the difficulty of the task. At both the central and state levels, however, Indians have shown vision and courage in pursuit of a just peace.