In a side-room at TGI Fridays off US Highway 22, the chicken wings are free, but the beer is not. The talk is optimistic, but the recent memories of vivid disappointment are right there under the surface.

Above the bar, subtitled television pundits are previewing a tense night of winner-takes-all October baseball.

And in the booths by the window, Democrats have come to meet the candidate they hope is part of a rising wave set to overwhelm Donald Trump and the Republicans in the midterm elections in November.

“I’m still traumatised by 2016; we all are,” said social worker Christine Ribaudo, one of the first to arrive at the event to meet Tom Malinowski, the Democratic candidate trying to unseat Republican Leonard Lance, who has represented New Jersey’s seventh congressional district for 10 years. “I’m taking nothing for granted this time.”

For months it had seemed that the political energy across the US was all with the outraged Democrats. First, there were strong special election results leaving a trail of clues in traditional Republican heartlands like Kansas, Alabama and western Pennsylvania. Then there was the emergence of a new wave of highly motivated leftwing candidates such as Alexandria Ocasio-Cortez in New York winning primary contests to force out older, male and often more centrist Democrats.

After two years of protest and activism, Democrats out for revenge began to dream of neutering Trump by taking back both the House and the Senate from Republican control in the 6 November elections. Each fresh Trump stumble seemed to drive the president’s hardcore supporters further underground and raise Democratic hopes.

But the ugly battle over the supreme court confirmation of Judge Brett Kavanaugh has changed the mood, given an energy boost to Republicans and left Democrats wondering if they might be heading for another soul-crushing result.

For Democrats, the comeback has to start in places like this TGI Fridays in Springfield, New Jersey, – a district that goes from rural farmland in the west, via Trump’s expensive Bedminster golf club in the middle, to the built-up east, where commuters have a daily battle to reach New York City.

“Exciting, isn’t it?” said Ribaudo. “It feels like we are in a very energized district.”

The district has sent a Republican to Congress for 37 years, but it is one of 25 Republican-held House seats across the United States where Hillary Clinton beat Donald Trump in the 2016 presidential race. The calculation sounds simple: win 23 of them and the Democrats would have gained enough ground to take back control of the House. With control of the House, they would gain the power to block, investigate and even attempt to impeach Trump.

Public confidence in polling has been sorely undermined since 2016, when virtually every pundit and poll failed to foresee a Trump victory. But in lieu of hard facts, every new poll that indicates a strengthened Republican lead in traditional strongholds like Tennessee and Texas heightens the impression that they have momentum.

Add to the mix that Trump is back in full cry night after night telling his rallies about the danger posed to America by Democrats who he claims have become an “angry leftwing mob”.

Trump is exuding triumphalism after Kavanaugh’s confirmation and has racked up a few more political wins: a rewritten trade deal with Canada and Mexico, unemployment at a historic low of 3.9% and an economy growing at 4%.

It’s not a naturally occurring weather event. We have to make it happen Tom Malinowski

So, is the great Democratic surge about to collapse?

“It’s not a naturally occurring weather event. We have to make it happen,” said Malinowski, the Democratic candidate in New Jersey 7, who once served in Barack Obama’s state department. “It’s not something any responsible candidate in a swing district can count on. We have to do it ourselves, one congressional district at a time.”

Cautious and careful in his answers, the Polish-born former Washington director for Human Rights Watch thinks his race is first and foremost about economic issues. Trump’s tax reforms will hit this district of middle-class homeowners who face new limits on reclaiming their high local and state taxes.

“No sane person with recent American political history in mind would be too confident. But it feels like a very close race and I think that also will inspire people to turn out. Most Americans live in a congressional district where they know who’s gonna win,” he said. “This is one of the few where the outcome is in doubt and therefore our votes count for more. There is a scenario where this district tips the balance in Washington. I think that will inspire people to come out.”

Tom Malinowski meets Democratic supporters in Springfield, New Jersey Photograph: David Taylor/The Guardian

Getting out the vote is crucial, because turnout is notoriously low in the midterms. Presidential election years usually see around 60% of Americans showing up to vote, whereas in the midterms it is a struggle to hit 40% turnout.

Two fragments of evidence are encouraging Democrats to believe their voters are ready to turn out this November in numbers that make it feel more like a presidential election year.

First, the number of registered Democrats in the district has increased by 33,000 since 2014. The same pattern is visible in at least 19 key seats across the country

Then there are the women.

For most of the two years since Trump won the presidency, it has become obvious that women have been highly organised in their opposition to him and his policies. Many more women are running for office or finding direction and purpose through a network of grassroots groups that did not exist in 2016.

Take freelance editor and mother of two Lillian Duggan. Five days after Trump’s win she set up a Facebook group in her hometown that has become a grassroots community advocacy organisation with a board of nine women, a weekly newsletter that goes to 450 people and more than 2,300 members on social media.

Duggan had a modest history of activism – mostly phone calls in aid of Obama and Clinton campaigns, but has had her life taken over by the group, Westfield 20/20, which has lobbied politicians at the state level, demonstrated outside Lance’s office, helped flip the Westfield town council to Democratic control and is now active in getting voters out.

“We have a chance of winning,” she said. “The polls seem to be a dead heat but we are trying not to pay too much attention to that – polls can be wrong as we all learned a couple years ago.

“We know it’s easy for us to feel the energy, see the signs up on lawns in our towns and feel very positive, but the reality is we’re not representative of the entire district. There are places that are more conservative.”

In Warren county’s Washington Township, once a hub of musical instrument manufacture, the Washington Diner serves the American classics along with both CNN and Fox News on screens above the counter.

But at the other end of West Washington Avenue, there was no such bipartisan spirit on show. Mena Shaddow, 70, and Jennifer English, 50, were staging a pro-life vigil outside a Planned Parenthood clinic where they intended to have a presence for 40 days as part of a global anti-abortion campaign.

Both women voted for Trump. “There’s a lot of things he doesn’t need to say – he’s got a big mouth – but I think he genuinely cares for people,” English said. “He’s certainly not perfect, but I do believe his heart is in the right place – and he has stayed faithful to the pro-life cause.”

Asked about the likelihood of a Democratic surge in November, Shaddow said: “I don’t think that is going to happen at all. The media see what they want to see – the reason Trump won has carried over,” she said, emphasising that he is a businessman and not a politician and has done in office what he said he would.

“There’s a lot of us,” she said. “I’m sorry if that’s not what you wanted to hear.”

Democrat Heidi Heitkamp of North Dakota faces an uphill battle to keep her Senate seat. Photograph: Bruce Crummy/AP

In suburban parts of major US cities, college-educated women are seen as a potentially decisive force that could help Democrats make gains in the House, in governor’s races and in state legislatures.

However, the Senate is a much harder proposition for the Democrats, even though Republicans hold a seemingly tenuous 51-49 grip on power.

Just 35 Senate seats are being fought this year and 26 of them are being defended by Democrats, so there are more opportunities for defeat than victory. The terrain is tough too – 10 of those Democrats are battling to keep seats in areas where Trump won in 2016, including five states where he won by more than 19%.

As Charlie Cook, editor of the Cook Political Report, put it: “It’s like there are two different elections taking place. One for House, governor, state legislature where there is a very clear blue wave out there for Democrats and I think Dems are gonna have a really, really good year.

“In the US Senate it’s like that election is being held in a different country and a different year. You can have a really big wave but for that wave to reach West Virginia and Indiana, North Dakota, that’s kinda hard.”

Cook is tipping the Democrats to make gains of between 25 and 45 seats to take control of the House.

Midterms are always a referendum on the president and usually offer a negative judgment, especially when the president’s approval rating is low. In 2010 when the Tea Party wave gave President Obama a “shellacking” in the midterms, his approval rating was down at 44% and Republicans picked up 64 House seats. Trump’s approval rating is currently at 42%.

Money matters too, and Democratic candidates are outraising Republicans in dozens of House races – limiting the ability of secretive dark money from Super Pacs being used to overwhelm them.

“This blue wave is turning into a green avalanche in that Dems are burying Republicans in cash. Their fundraising has shattered records,” David Wasserman of the Cook Political Report said.

It turned out that Donald Trump was a better fundraiser for the Democrats than Barack Obama and Nancy Pelosi ever were.”

In Westfield, Lillian Duggan said dismay at Trump’s 2016 victory had created a new sense of purpose and community.

“I have met so many people in my town I didn’t know before, or found people I didn’t know had similar values and concerns. People just didn’t talk about it then.”

And if that blue wave does not materialise and November brings only another defeat? “Well, I think we rest up and collect ourselves and figure out how to address the issues.

“If we don’t win this race, 2020 is not going away.”

