THE PRESIDENT has proposed a two-stage, 20 percent increase in the minimum wage, which, when fully effective a year from September, would pretty well restore the purchasing power the wage was allowed to lose in the 1980s. Congressional Democrats favor the step, and enough Republicans favor something like it that an increase almost surely commands majority support in both houses.

The House Republican leadership, which opposes an increase but lacks the votes and wants to avoid a repeat of the divisive battle it ended up losing the last time the issue arose in 1996, says it will bring a bill to the floor sometime this year. The increase may be a little less, and, as in 1996, is likely to be combined with a spray of tax and other small-business benefits intended to make the bill more palatable to its stoutest opponents.

The Senate leadership may be more disposed to resist, but if it does, it too risks a replay of 1996, when Democratic proponents all but shut the Senate down by offering the minimum wage increase as an amendment to just about any other bill that came along, until finally they prevailed.

The arguments for and against an increase are always the same. Critics point out that not all those working at the minimum are poor; many are teenagers or other secondary earners in families relatively well off. The wage thus becomes an inefficient way of aiding the needy, the more so, the critics argue, because the higher cost to employers leads to a loss of jobs.

Supporters dispute whether the job loss is that serious and note that most of the people working at the minimum are in the lower reaches of the income distribution even if some are not. They note as well that an increase in the minimum also tends to help lower-paid workers in the zones just above the minimum. On balance, they argue that it helps the people it is intended to help.

Our sense is the minimum ought to preserved in terms of what it will buy. The price of passing a bill could well be, if not an outright cut, a stretch-out of the dollar the president has proposed; that has sometimes happened in the past. But a full-time, year-round worker earning the president's $6.15 an hour next year still will not earn enough to support a family of three at the poverty line; that ought to be a factor in the decision. Nor should the non-wage amendments to the bill include poison pills whose only purpose is to force supporters to vote no. This is a serious question that has to do in part with basic fairness, and that deserves an up-or-down vote on its own.