By Jeremy M. Lazarus

Democrats remain two seats short of taking control of the 100-member Virginia House of Delegates based on official local counts completed Tuesday.

With recounts anticipated for at least three seats for which Republicans barely edged their Democratic rivals, it could be December before Virginians will officially know whether the General Assembly’s lower chamber will remain in GOP hands.

As it stands now, Republicans are clinging to a 51-49 margin, a far cry from the dominating 66 seats the GOP held in the last session.

Still, the Democrats’ pickup of 15 seats is viewed as remarkable by political experts.

It did not happen by accident, said Joshua Ulibarri of the New York-based Lake Research Partners, a group the state Democratic Party employed to help guide the election battle.

Speaking to reporters last week, Mr. Ulibarri said that one key to the array of Democratic victories is the fact the party was relatively united.

He said polling after primary elections in June showed that “the party came together relatively quickly.”

Lake Research polling found that within weeks, 80 percent of Democrats were supportive of the statewide ticket of Ralph Northam for governor, Justin Fairfax for lieutenant governor and Mark Herring for attorney general.

He said that was a far higher percentage than in 2013 when Terry McAuliffe became the Democratic candidate for governor. Mr. Ulibarri said internal polls four years ago showed 65 percent of Democrats were ready to back the statewide ticket.

With that kind of unity, he said the party saw an opportunity to target the 17 House districts that had Republican delegates, but that Democrat Hillary Clinton won in the 2016 presidential election.

With new people signing up to challenge GOP delegates and seeking open seats — many in parts of the state where Democrats previously failed to compete — Mr. Ulibarri said his staff conducted polling and focus groups to identify the issues of most concern to voters in each district, including health care, voting rights and the environment.

Those findings were used to help Democratic candidates at the state level and those running for House seats to shape campaigns that spoke to those concerns.

The final step was to arrange a strong get-out-the-vote effort to help ensure that people, particularly party supporters, went to the polls.

The results, he said, show that this targeted effort worked well.

No matter what happens, he and others note that Democrats will have a bigger say when the General Assembly convenes in January.

The battle still rages in the trio of districts where Democrats fell short.

A lawsuit has been filed in the 28th District in the Fredericksburg area seeking to force the Stafford County Electoral Board to count 55 absentee votes found a day after the Nov. 7 election.

The board refused to count the votes and on Tuesday certified that Republican Bob Thomas won by 83 votes over Democrat Joshua Cole for the seat currently held by outgoing Republican House Speaker William J. Howell. Mr. Cole is not conceding the race until there is a court-ordered recount, which is likely to happen in December.

In the two other races where recounts also are certain, incumbent Republican Delegate Timothy D. Hugo of Fairfax officially won by 106 votes over Democratic challenger Donte Tanner in the 40th District, and incumbent Republican Delegate David E. Yancey of Newport News edged Democratic challenger Shelly Simonds by 10 votes in the 94th District.

Democrats need to pick up just one of those seats in a recount to gain a power-sharing arrangement with Republicans, as both parties would then have 50 seats. The House would again be under Democratic control if Democrats are declared victorious in two of the recounts.

However, based on past recounts, most experts are putting long odds on any change taking place during the recounts.