Start with a dedicated group of supporters and a strong war chest of campaign contributions.

Add a desirable list of projects to be funded and local sales tax levies can pass public muster despite a sagging economy and an anti-tax political climate, experts said in the wake of Cobb County’s passage of a tax extension Tuesday.

Proponents of Cobb’s special purpose local option sales tax extension successfully used all those elements in winning the razor-thin victory. The extension passed by 79 votes out of almost 43,000 cast. It keeps Cobb’s sales tax at 6 percent.

The hard-fought Cobb election, which pitted the development community against tea party-style opponents, could be a preview of the campaign -- if not the outcome -- of a regional transportation SPLOST scheduled next year. It also provides some insight into what voters are willing to support as state lawmakers work on changes to the state’s tax laws.

Like Cobb’s referendum, the regional SPLOST will depend on turnout and keeping the issue from being overshadowed by presidential politics, said Harvey Newman, Georgia State University’s department of public management and policy.

The four-year extension of the Cobb’s current one-percent sales tax is expected to generate $492 million for parks, roads and facilities improvements and renovations for Cobb and its six cities.

“Turnout was low and in that instance it’s whatever side can get the most turnout is going to win,” said Newman . “Money certainly helps, but it’s not a guarantee of course. But it is important because motivating voters is so difficult for a non-concurrent election of this sort.”

Cobb’s SPLOST referendum, held as a single-item special election on Tuesday, generated a turnout of about 11 percent.

State election code allows for an automatic recount in candidate elections, but not for ballot questions. The county board of elections must call for a recount in such votes, and Cobb’s had no plans to do that, elections director Janine Eveler said Wednesday. Members of the Cobb County Taxpayers Association, which opposed the SPLOST, planned to visit the elections board Thursday and find out more about a recount and any outstanding votes, said Lance Lamberton, the association’s president.

Fifty-eight provisional ballots will be tallied after 5 p.m. on Friday before the election is certified Monday morning at 8 a.m.

“I truly believe it’s about a grassroot effort and having a core committee and consistently getting the message out,” said Rose Wing, leader of the Citizens for Cobb’s Future group supporting the SPLOST. “Cobb voters have supported SPLOSTs in the past, but it’s important to keep going out and following up on the message

Wing’s group raised $232,000 — much of it from community improvement districts, developers and companies that do business with the county — to conduct polls and surveys and for voter education, and to fend off strong anti-tax opposition from groups like the tea party, which raised about $500 in cash.

Officials in Bartow County, Cobb’s northwest neighbor, are still weighing whether to call for a SPLOST vote, which could happen as early as November.

“We have certainly been paying attention to whether people are willing to continue to support SPLOSTs referenda, and it appears that they are,” said Steve Bradley, Bartow’s county administrator. “With the way the economy is, it is still unknown whether Cobb’s close vote reflects the tough times or if it’s just a trend in Cobb to have a little more difficulty in passing [SPLOSTs] then elsewhere.”

Cobb’s current SPLOST, approved in 2005, passed by a mere 114 votes, so close calls are nothing new there.

Voters in Newton, Barrow, Jackson and Madison Counties passed county and schools SPLOST on Tuesday by significantly wider margins than in Cobb.

The close vote underscores that Cobb residents on both sides of the issue are are fiscally conservative, said Tim Lee, Cobb’s commission chairman. With the vote passed, Lee’s attention turns to balancing the county’s budget, which is $28 million in the red, and knowing that residents will be closely monitoring how their tax dollars are spent.

As for the regional SPLOST, the outcome could turn on how many people see a direct practical benefit, said University of Georgia political science professor Charles Bullock.

“If you have spent enough time sitting in a traffic jam and have to do that on a regular basis, I think you will be willing to pay for that,” said Bullock. “If you are inconvenienced you are more likely to vote for it.”