ARLINGTON COUNTY has been substantially remade in the last couple of decades, mostly for the better. An influx of shops, restaurants and apartment buildings, mainly near Metro stations, has attracted a new generation of ambitious young professionals and lent the county a cosmopolitan gloss. About 70 percent of adults hold degrees from four-year colleges, and a quarter of all residents were born in another country, making Arlington one of the most highly educated and diverse places in ­America.

The transformation, accompanied by rapid growth, has also produced growing pains, saddling the county with a shortage of affordable housing, acute demands for public transit and strains on its generally excellent public schools.

For the most part, the changes have been adeptly managed in recent times by the five-member, all-Democratic Arlington County Board, which has exercised fiscal discipline and sound judgment. Two of the five incumbents on the board — J. Walter Tejada and Mary Hughes Hynes — are seeking another term in office in elections Tuesday. Both deserve it.

Mr. Tejada, who is finishing his second four-year term, is the first Hispanic elected to public office in Arlington, and he has made himself a champion of the county’s minority communities, which together make up more than a third of residents. His focus has been somewhat narrow, and he’s not known as one of the more detail-oriented members of the board. But there’s no question about his commitment in fighting for affordable housing, immigrants and the disadvantaged.

Ms. Hynes, a former school board member now finishing her first term on the county board, has been a fastidious, conscientious force for good government and common sense. She has combed through the county’s plans to upgrade parks and recreational facilities, pushing to ensure the funding needed to keep them in good shape. She’s also the newest of Northern Virginia’s appointees to the Metro Board of Directors.

A third candidate, Green Party member Audrey Clement, is challenging the two incumbents. (The top two vote-getters among the three contenders will be seated on the board.) Ms. Clement is well informed, but she is far better at articulating what she is against — including much of the high-profile development that has taken place or is planned in the county — than what she is for.

By her reckoning, Arlington’s growth has been helter-skelter and has outstripped supporting infrastructure. But Arlington lies at the heart of one of the nation’s most dynamic metropolitan areas. The key to sensible policy there is to elect leaders who will manage growth wisely, not anti-growth candidates such as Ms. Clement, who would try to stop it in its tracks.