Justin Wilson, vice mayor of Alexandria. (Patricia Sullivan/The Washington Post)

THE CITY of Alexandria, one of Virginia’s most lopsidedly Democratic bastions, is beset by a polarizing, internecine mayoral primary. Its protagonists — Mayor Allison Silberberg and Vice Mayor Justin Wilson — are so stylistically dissimilar that they sometimes seem like residents of different cities, if not distant galaxies.

In fact, the contrast is more than stylistic. It’s about whether Alexandria should cling to a gauzy, hidebound, ossified version of itself or embrace forward-leaning policies that would prepare the city for a new era. Ms. Silberberg represents the former vision; Mr. Wilson the latter.

Mr. Wilson is the better choice in the June 12 party primary, whose winner is a shoo-in to become mayor. He has been the real leader on a city council whose titular head, Ms. Silberberg, is prone to time-wasting, rambling tangents at public and private meetings and sniping at controversial development proposals.

Mr. Wilson — astute, practical, no-nonsense — has both a keen strategic sense of how to position Alexandria to cope with an era of slowing federal spending and an impressive command of the city’s $730 million operating budget — and its limitations, given the acute challenges facing the city. He has been proactive in addressing the fact that Alexandria’s revenue growth has failed to keep abreast of its burgeoning population, overstretched services, rusting infrastructure and aging schools, where more than half the students are from needy families, making them eligible for free or reduced-price lunches.

By contrast, Ms. Silberberg is notorious for casting lone “no” votes on the seven-member council — on budgets, land use and much else — generally without offering a viable alternative. By being on the short end of those decisions, she has endeared herself to a cohort of constituents, many of them in Old Town, who tend to oppose initiatives that would modify the city’s historical character.

It’s a suitable approach for a gadfly; it has worked less well for a mayor. Alexandria, a city of 160,000 residents, is more than than a quaint Old Town whose appeal to tourists has come under growing competitive pressure from dynamic new development at National Harbor, across the Potomac River in Maryland, and the Wharf, in the District. Ms. Silberberg, whose grasp of policy details is impressionistic, often comes across as ill-prepared and tends to fixate on projects’ tertiary details.

Ms. Silberberg’s fans in Alexandria appreciate her willingness to listen, for hours on end, to constituents’ objections to various projects. But in the local business community, and among officials in neighboring localities, she is regarded as well-meaning but digressive, removed from the hard work of local governance.

That sets the wrong tone for a city grappling with Alexandria’s set of challenges. Mr. Wilson would be an upgrade.