PORTSMOUTH — What looked like a decisive victory for Democrats in Tuesday’s Town Council election could turn into a complete sweep, potentially leaving Republicans without a single seat on the seven-member board.

And one of the casualties could be Town Council President Keith E. Hamilton, a popular Republican incumbent who now finds himself in a dead heat with Democratic newcomer Alexander Roberts for the seventh and final seat.

Updated election results released Wednesday morning showed Hamilton and Roberts with exactly 3,555 votes apiece, setting up a nail-biting finish that may not be resolved until at least 4 p.m. on Tuesday, Nov. 10.

That’s the deadline for military and overseas ballots to arrive, according to Portsmouth Registrar of Voters Jacqueline Schulz, who said Wednesday afternoon that additional ballots still need to be reviewed and counted.

“We have 25 provisional ballots,” Schulz said, adding that election workers were reviewing them to determine which could legally be counted.

Those ballots are cast by voters whose eligibility could not be immediately verified at the polls. Not all provisional ballots necessarily make it into the final tally.

In addition, Schulz said, there are approximately three ballots that will need to be counted manually because they could not be processed by the voting machines on Election Day.

The number of outstanding military and overseas ballots was not immediately available. Schulz said she planned to prepare a mail ballot report that would provide more precise figures.

Regular mail ballots were required to arrive at the Rhode Island Board of Elections by 8 p.m. Tuesday, when polls closed. Military and overseas voters, however, have until Nov. 10 for their ballots to be received.

Schulz also said she was uncertain whether all mail ballots received by the state, including those collected from the drop box at Portsmouth Town Hall and delivered Wednesday morning, had been included in the latest totals.

A stunning reversal?

The possibility of a Democratic sweep adds another dramatic twist to an election that already produced major changes in Portsmouth’s political landscape.

Democrats captured six of the seven council seats in Tuesday’s initial returns, defeating several longtime incumbents and dramatically shifting the balance of power on the council.

Among those defeated were independent Mary A. McDowell and Republicans Sharlene M. Patton and David G. Reise.

Hamilton, however, appeared to have survived the Democratic wave, securing the final seat by a narrow margin in the initial returns.

Wednesday morning’s updated numbers erased that advantage entirely.

If Roberts ultimately finishes ahead, Democrats would control all seven council seats, an extraordinary turnaround for a town where Republicans and independents have maintained a significant presence in local government over the past two years.

Hamilton’s defeat would be particularly striking given his leadership position on the council and his years of service to the town.

Recounts are possible

Schulz said Portsmouth has experienced similarly close elections before.

She recalled a previous council contest involving Leonard Katzman and Elizabeth Pedro, as well as recounts in past races for town clerk.

Any candidate seeking a recount must submit the request through the Rhode Island Board of Elections, she said.

Even after the remaining ballots are counted, the results will not immediately become official.

Schulz said Portsmouth’s board of canvassers has already posted a meeting to certify local election results, but cannot take that action until the state Board of Elections certifies the statewide election.

“We have posted our meeting to certify local results, but our board of canvassers cannot certify until the Board of Elections certifies the statewide election,” she said.

For Hamilton and Roberts, that means at least several more days of uncertainty.

And for Portsmouth Democrats, the possibility of something that seemed unlikely just a day earlier: a clean sweep of the town council.