WASHINGTON — Six months ago, Democrats were cautious in their optimism. They talked a lot about a strong 2018 that might chip away at the GOP’s majority in Congress.

But after winning a pair of governor’s races, more than a dozen state legislative contests, and a Senate seat in a deep red state over the last month, they are no longer holding back.

“Republicans are going to need to appreciate this wasn’t all about Roy Moore and sexual assault,” said J.B. Poersch, president of the Democratic-aligned Senate Majority PAC. “This is a bigger issue.”

Party leaders are eagerly anticipating the 2018 midterm elections in the aftermath of Democrat Doug Jones’ upset victory in Alabama, convinced they can now win majorities in the House and Senate in addition to a fleet of marquee gubernatorial races. To them, the victory in Alabama was the culmination of victories last month in Virginia and New Jersey, where the party swept to wins in both gubernatorial and state legislative races.

“There’s no other way to argue it to except for the objective fact that our people are voting in droves, and their people are staying home in droves,” said Gov. Jay Inslee, governor of Washington and chairman of the Democratic Governors Association. “And when that happens, you have massive swings toward the blue part of the spectrum.”

Inslee’s group is targeting dozens of governor’s seats held by GOP incumbents next year. National Democrats, meanwhile, are trying to gain 24 House seats required for a majority and even the two Senate seats necessary for control of that legislative chamber. Democrats are defending twice as many Senate seats next year as Republicans, including 10 in states that Trump won in 2016.

Even at this late stage of the election cycle, many Democratic officials are plotting ways to expand the electoral map even further into GOP territory, confident that a victory in a state as conservative as Alabama will persuade once-hesitant recruits to jump into previously overlooked races. An expanded map might not guarantee additional victories, they say, but it can at least put additional pressure on the Republican Party.

“Not only have we re-examined every single potential race we could get into, every candidate who has said to us, ‘We’re on the fence,’ we were back calling them at crack of dawn this morning,” said Dan Sena, executive director of the Democratic Congressional Campaign Committee, the political arm of House Democrats.

Sena said House Democrats have tried to recruit strong candidates in even long-shot House races, hopeful that results in Alabama and some state delegate races in Virginia are proof that Democrats can score unexpected victories across the map. He cited as an example Illinois’ 12th Congressional District, where the party thinks it can defeat incumbent Republican Rep. Mike Bost in a place that gave President Donald Trump 55 percent of its vote just last year.

Democrats caution that they have a lot of work to do over the course of a long 11 months until Election Day 2018.

But public polling backs up the party’s bullish view: A survey from Monmouth University released Wednesday found that Trump’s approval had slumped to 32 percent this month, a record low for the poll. Midterm elections are traditionally referendums on the incumbent presidency, with the incumbent’s popularity, or lack thereof, a huge factor.

The opposition party has been the beneficiary of wave elections during the last three midterm seasons: in 2006 (when Democrats won the House and Senate), 2010 (when Republicans won the House), and 2014 (when Republicans won the Senate).

Many Democrats see a direct parallel in the current political climate to 2010, when Republicans swept to massive gains in the House and Senate after the first two years of President Barack Obama’s tenure.