Last Updated at 8:27 a.m. on Nov. 9, 2017

At the legislative level, Democrats had a better election night than they could have dared to hope for, making a huge comeback in the Virginia House and picking up seats in special elections from Georgia to Washington state.

"The most significant thing about the Democrats winning power is that they'll have the opportunity to set the agenda of what's voted on," says Rich Stolz, executive director of OneAmerica, a group that advocates for immigrants and refugees in Washington state.

There, a Democratic win in a Seattle-area Senate seat gave Democrats a one-seat majority in the chamber and, with it, control of all the political branches of government. Coupled with their victory in the New Jersey governor's race, Democrats now have full control of nine states.

They still have a long way to go to reach parity, given GOP control of 26 states. But the fact that Democrats have erased a 16-seat Republican majority in the Virginia House, or come awfully close (depending on recounts), has to be encouraging for Democrats heading into next year's elections.

Following their historic sweeps in the 2010 and 2014 cycles, Republicans not only hold control of two-thirds of the nation's legislative chambers but enjoy two-thirds or 60 percent majorities in most of those. Suddenly, those large majorities don't seem as secure.

Democrats, whose strength has been mostly limited to metropolitan areas in recent years, showed in Virginia that they can win just about any suburban seat. And there are lots of those around the country.

"During the Obama administration, Democrats lost almost 1,000 state legislative seats," says Steven Rogers, an expert on legislative elections at St. Louis University. "The gains in Virginia and New Jersey are the beginning of the Democrats taking many of these seats back."

Democrats added modestly to their majorities in New Jersey, picking up a seat or two in either chamber. The shocker was in Virginia House races, where the GOP went into the election with a 66-to-34 majority. Democrats needed to gain 17 seats to take power. Despite the fact that Hillary Clinton had carried 17 districts in last year's presidential election, even the most optimistic Democrats thought this would be a rebuilding year. They would have welcomed gains of up to 10 seats.

As things stand on Wednesday morning, Democrats appear to have won 15 seats -- one short of what would be needed to tie the chamber. There are four races close enough to trigger recounts, with each party in the lead in three of those. Depending on how things go, either Republicans or Democrats could end up in control, or the chamber could end up tied.

It's the most House pickups by Virginia Democrats in a single year since the 19th century.

"This was an extraordinarily successful nights for Democrats in the House of Delegates," says Stephen Farnsworth, a political scientist at the University of Mary Washington. "They've outperformed optimistic expectations."

In the Virginia Senate, which was not in contention this year, Republicans hold a single-seat majority. In recent years, it's been Republicans who have speculated in the aftermath of elections in the South that they can maybe get one or two legislators to change parties, or have the governor appoint people to state jobs who represent districts that appear ripe for the taking in a special election. This time, given Ralph Northam's convincing victory in the governor's race, it's the Democrats' turn.

All over the country this year, Democrats had scored scattered gains in special legislative elections in states such as Florida and Oklahoma. Their imminent takeover of a Georgia Senate district -- both candidates who are moving to a runoff are Democrats -- means the GOP will lose its supermajority in that chamber. Democrats picked up two other seats in Georgia, as well as seats in Michigan, New Hampshire and several other states.

The big win for the party Tuesday came in Washington, where Manka Dhingra's victory gives the Democrats a narrow majority in the Senate. The race was hotly contested -- drawing some $9 million -- but was never really in doubt following Dhingra's victory in the all-party primary in August.

Democrats, who have been frustratingly close to unchallenged power in Olympia, will be tempted to ask for the moon.

"The legislature hasn't been fertile ground for bold policies on the climate crisis," says Jesse Piedfort, executive director of the Sierra Club. "There's a compelling need to get working on some of these issues because we feel we're making up for long time."

The reality, however, as Piedfort recognizes, is that 2018 will be a short legislative session.

"It is important to note that Washington state has a two-year budget cycle, and 2018 is a supplemental budget year," says Tara Lee, a spokeswoman for Democratic Gov. Jay Inslee. "So it will be a short session and movement on policy proposals usually happens in budget years."

Groups on the left had been strategizing before the election about what's realistic to ask for. They'll look first to legislation that has already passed the state House, such as a "reproductive parity" bill that would require insurers that offer maternity care to pay for abortions. Supporters have been pushing the measure since 2012, so far without success.

"We anticipate there is ample energy to push this through," says Tiffany Hankins, executive director of NARAL Pro-Choice Washington. "We're optimistic that this will be one of the top priorities for the state Senate."

The tight schedule means that progressives will be jockeying for legislative bandwidth. There will be pressure to call an immediate special session to address the need for a new capital budget, as well as hopes of raising funding for education in the wake of a state Supreme Court ruling on school financing.

"There will be a lot of realism around what they can move," says Stolz, the immigration advocate. "Consensus among Democrats will be key."

Given the party's slim majorities, Democratic leaders may shy away from doing a "full Seattle" in pursuing liberal legislation.

"With a one-seat majority in the Senate and a two-seat majority in the House, they might be so cautious they don' t do anything," says Chris Vance, a former chair of the Washington GOP.

The landscape may not be as promising for Democrats in every state. Not many legislative bodies have as many GOP-held seats that were carried by Clinton as the Virginia House.

But Democrats around the country are likely to be emboldened by their strong showings in this year's elections. In Virginia, the Democratic Party had historically left dozens of seats uncontested, but this time the party and its allies -- including many political groups that have sprung up on the left in the wake of President Donald Trump's election, including Flippable, Run for Something and Sister District -- helped recruit and fund candidates around the state.

"More Democrats ran in Virginia than before, anticipating electoral success, and the results Tuesday rewarded that ambition," says Rogers, who is writing a book about legislative contests. "In 2018, Republicans will likely lose hundreds more state legislative seats."

This story is part of our 2017 elections coverage.