Arlington halted plans to build a 4.9-mile streetcar line that would have run along Columbia Pike from Skyline Plaza in Fairfax County to Pentagon City. (Joseph Victor Stefanchik/For The Washington Post)

In proudly progressive Arlington, few like to admit that the county suffers from class and racial divisions just as in other places that are supposedly less enlightened.

But the county’s decision Tuesday to kill two long-planned streetcar lines has cast a light on the divide — and will probably deepen it.

Lower-income, racially diverse South Arlington has been counting on the Columbia Pike and Crystal City streetcar projects to deliver a jolt of growth. Residents there hoped the new transit lines would lead developers to rebuild aged apartment buildings and spruce up dreary strip malls.

Instead, the county’s abandonment of the streetcar has instantly created major doubts about the area’s future and made it less competitive.

(Related Five steps to doom for Arlington streetcars)

“There’s a lot of orphans out there on Columbia Pike who invested based on the streetcar,” said Christopher Leinberger, a land-use expert and research professor at George Washington University’s business school. “The demand is going to go somewhere else.”

In effect, Arlington just told its least prosperous residents: “You want streetcars to upgrade your neighborhoods? Too expensive. Keep riding the bus.”

Tuesday’s vote to kill the streetcars came as a direct result of the reelection Nov. 4 of anti-streetcar County Board member John Vihstadt (I). Voting patterns in that race illustrated the divide between the two Arlingtons.

Affluent, mostly white North Arlington overwhelmingly supported Vihstadt. By contrast, his opponent, Alan Howze (D), won his biggest margins in precincts in South Arlington along the streetcars’ proposed route.

The streetcar wasn’t the only issue in the election, but it was the biggest one, by far. It effectively served as a referendum on the transit projects.

In response, b oard Chairman Jay Fisette (D) and board member Mary Hynes (D) have switched their positions, giving the anti-streetcar faction a 4-1 majority on the board.

It’s not the first time the county has dissed Columbia Pike. Planners passed over South Arlington when Metro was built. They chose to locate the Orange Line in North Arlington, investing billions of dollars to create what became the booming Rosslyn-Ballston corridor.

A map of the Columbia Pike initiative

Walter Tejada (D), the only board member who voted Tuesday to preserve the streetcar projects, recalled the history in a statement: “Columbia Pike lost out. No Metro. . . . As a result the Pike area has not prospered as well as those who got the Metro.”

He added, pointedly: “The Pike is the most diverse corridor in Arlington, with 65 percent of the population as minorities.”

Arlington’s decision also dashed hopes of a less-affluent corner of neighboring Fairfax. The streetcar was supposed to cross the county line and create a much-needed transit connection with Baileys Crossroads and particularly the Skyline development there.

To a great degree, Fisette and the rest of the county’s Democratic leadership have only themselves to blame for the debacle.

They moved too late to build a consensus within Arlington that the streetcars, albeit costly, were the best way to promote prosperity in South Arlington. That in turn would expand the tax base and benefit the entire county in the long run.

The board and county bureaucracy also squandered voters’ goodwill with some foolish, overpriced projects, including the notorious $1 million bus stop.

Still, a class bias was evident in some controversies in addition to the one over the streetcar. In particular, resistance arose over the cost of a proposed public aquatics center next to Crystal City.

That triggered grumbles that Arlingtonians in other parts of the county didn’t appreciate the need for the pool, because they can afford to join country clubs or other private aquatics facilities.

Streetcar opponents argued that expanded bus service on Columbia Pike would be cheaper than streetcars and interfere less with traffic. The burden is now on them to make buses work to encourage growth and redevelopment in South Arlington.

Streetcar supporters fear buses won’t offer enough capacity or attract enough riders. They also worry that without rails in the ground, developers won’t have confidence that the transit service will be lasting.

Technical arguments aside, the question remains of whether the county just has a streak of unease about Columbia Pike.

“I think there’s a [false] presumption that it’s not a safe place or not a desirable place to live,” said Juliet Hiznay, a civic activist and former president of the board of the Columbia Pike Revitalization Organization.

“There may be a kind of unspoken thought that the bus is good enough for Columbia Pike, and it’s not,” she said.

I discuss local issues Friday at 8:50 a.m. on WAMU (88.5 FM). For previous columns, go to washingtonpost.com/mccartney.