Unrest Besets Scandal-Scarred Dade Union

Since taking over the troubled United Teachers of Dade two years ago, President Karen Aronowitz has raised membership numbers to a record high of 18,000 and negotiated a brand-new contract. But support for her leadership within the union has splintered to the point where she faces four challengers in elections next week.

Union officials credit Ms. Aronowitz for nursing the local in Miami-Dade County, Fla., through a dark period. Members of the union chose her as their first elected leader after it was discovered that longtime President Pat L. Tornillo Jr. and two other top officers had stolen more than $3 million from union coffers. With the thefts, a $13 million mortgage on a new headquarters, and a sharp decline in membership, Mr. Tornillo left behind a union that was nearly insolvent.

The American Federation of Teachers took over the union shortly after the scandal broke, bringing in Mark Richard, a labor lawyer and the president of the United Faculty of Miami-Dade Community College, to repair the damage. The union has since bounced back, officials say. “On the political front, the financial front, the membership front, and on contract negotiations, they have done extremely well,” said Mr. Richard, who ran the UTD...