With politics in America more polarised than any time since the 1960s, there is one thing that all the parties can agree on this crucial election year - the power of web-based activism.
New York City may be a bastion of Democratic Party politics and support, but that didn't stop the Republican grassroots' campaigner-in-chief, Ralph Reed, from attending a downtown seminar in late May on politics and the internet.
The legendary right-wing organiser - who is leading the president's re-election team in the south-east - told his mainly left-leaning audience that local democracy was being regenerated through the internet.
That was plain to see a few nights ago, when hundreds of John Kerry supporters gathered in venues around the world, via the Meetup.com site.
Larissa Chernock (centre): "It's time to get Bush out"
The presumptive presidential nominee for the Democratic Party is not the first contender to harness the communication potential of Meetup.
Failed candidate Howard Dean mobilised thousands of supporters in every state and led the way in internet fundraising.
The organisation which he bequeathed after leaving the Democratic race, Democracy for America, has the largest membership of any political group on the Meetup site - 165,200 people.
Mr Kerry now comes in second, with 113,600, and the monthly meetings which anyone can organise and attend are being viewed by the campaign as crucial to its long-term success.
On a Thursday night at the end of May, loose groups of Kerry supporters gathered in London, Paris, Toronto, and across the whole United States.
In downtown Manhattan alone, five different Meetups were convened, mostly led by activists affiliated to the national Kerry organisation.
There was one notable exception. I joined up with an earnest group of about 15 young New Yorkers at the fashionable 88 Orchard Street cafe. Most lived locally, and had already attended at least one previous meeting.
"I found out about it from a friend who was doing a Meetup for owners of pug dogs," Liz Merker said. "I looked at the site and offered to volunteer to do something for the campaign straight away."
Leading the meeting was Kerry campaign volunteer Pagan Harleman, who had met other team officials last week to set out an agenda in order to give focus and direction to the evening.
After 20 minutes of chatting in the dimly-lit Moroccan-style basement festooned with cushions, a guest joined us with a puzzled look on his face.
It turned out that our new arrival, Dominic Pisciotta, who works for the city council, had organised another Kerry Meetup in the trendy bar next door:
"So there's another Meetup going on, on the other side of this wall," Ms Harleman said. "Are you running an ad-hoc group that has no idea what's really happening?"
Mr Pisciotta was contrite: "Yeah, basically that's it. We ordered drinks and stuff, so we can't really join you here."
An experienced Kerry-supporter was despatched to the bar next door to take control. When I wandered through shortly afterwards, a group of 20 people were gathered around a large table, sipping Mexican beers and margaritas, talking through the myriad ways that activists have devised to raise funds.
As Democrats outnumber Republicans by five to one here, fundraising for the real election fight in the so-called "battleground states" where the parties are close, is the chief preoccupation.
One activist organises weekly jogs through Central Park under the banner "Run Against Bush". Others organise telethons where people gather one evening a week to use their free cell phone minutes, and call voters in key states like Ohio or Florida.
The Meetup is an ideas forum for campaigners
The anarchic element of Meetup culture is at once its greatest strength, and also a weakness for the centralised campaign teams.
The Kerry and Bush regional headquarters want to harness the power of grassroots activists, but also must accept that they have no executive authority over them. Being "on message" goes against the Meetup ethos.
Ms Harleman was also keen to remind the group that the presidency is not the only thing at stake: "If the Republicans keep Congress and we lose the Senate race, we're looking at 15-20 years of Republican control. A Democrat president is only part of it."
Everyone at the Meetups has a slightly different reason for being there. For 24-year-old Larissa Chernock - a recent Harvard graduate - it's all about international stability:
"This election involves the whole world, and even though New York is a shoo-in for Kerry, we mustn't be complacent. He could be doing a little better and he's not as charismatic as say, Bill Clinton, but whether you love him or not, it's time to get Bush out."
That lack of real enthusiasm for Kerry is something tangible that is worrying party pollsters. Another young woman at the meeting put it this way: "None of us are here for Kerry, we are here because we hate Bush. Anyone but Bush would do for me."
Mr Pisciotta, organiser of the "rogue" Orchard Street Meetup, is putting his energy into beating Mr Bush, after the president supported the idea of a constitutional amendment to ban gay marriage:
"My partner and I have twins who are 14 months," he says. "When Bush came out against gay marriage that was my ticket to start speaking out. I grew up in Virginia which is real Bush country, so I know only too well where my interests lie."
After handing out copious sheets listing anti-Bush and pro-Kerry groups, several Meetup participants began discussing ways they could canvas the prized swing-voters face-to-face, without leaving the city.
Matt Townsend, 28, who lives just a few blocks from the café, volunteered to lead a "tourist outreach" group which will aim to seek out battleground state voters around Times Square, every few weeks:
"Being in the Meetup is better than sitting around in some stiff meeting with campaign staffers. I think it's a comfortable place to have some real ideas," the multi-media company writer said.
So if you are accosted by a group of young Kerry campaigners while you wait in line to buy a ticket for a Broadway show this summer, it's all part of the new web-led culture that is transforming the face of political campaigning in America.