When a union president not known for his reformist tendencies looks to be getting all reformist, union dynamics get mighty interesting.

This past summer United Teachers Los Angeles President A.J. Duffy made a secret agreement with the school district that allowed some 1,800 newly laid off teachers to jump to the top of L.A.'s substitute list, giving them priority over regular and in many cases veteran substitutes for this school year.

Subs happen to be bona fide members of the 48,000-member teacher union (who knew!) and they were hopping mad. Duffy made some attempt to calm the waters, telling them in a letter that his aim had been to stabilize schools that had been hard-hit in the July layoff and that he expected most of the laid-off teachers to end up subbing back at the schools where they had been employed full time. He had even hoped that, as the district's financial picture brightened, those teachers would get their jobs back, the subs would get back to work and all would be normal. He went on to explain the secrecy as a condition to which the union and the district had agreed for contract negotiations.

Many teachers, siding with the subs, didn't buy it. In a series of union meetings across the district, union members voted overwhelmingly to get Duffy to rescind the one-year-only deal. At stake, sub leaders said, were not only their own livelihoods but the seniority protections for all teachers.

We could guess that laid-off teachers, most of whom had only one or two years of experience, liked Duffy's plan. But such nontenured teachers are a small minority among union members.

The union's representative body is to take up the matter next month.