CAMP HILL, Pa. — One Monday morning late last month, three canvassers fanned out across a quiet neighborhood here, hoping to gauge and shape voters’ impressions in advance of Election Day.

But the three young men bearing iPads weren’t pushing the cause of Hillary Clinton or Donald Trump. Working on behalf of the conservative group Americans for Prosperity, they were urging undecided voters to oppose Katie McGinty, the Democratic candidate for Senate.

Jeremy Baker, a field director for AFP in central Pennsylvania, estimates he has knocked on 30,000 doors with his team. “Trump has a campaign office nearby, but I don’t see them out knocking on doors,” Baker said. “I’ve never seen a door hanger, I haven’t seen people walking around.”

Even in more populous areas of the state, like southeast Pennsylvania, Trump’s ground game has been invisible.

“They’ve started to see campaign people down there,” said Beth Anne Mumford, the Pennsylvania state director for AFP, who joined the canvassers that day. “But we haven’t seen presidential anywhere.”

With roughly one month until Election Day, and with absentee or early voting already underway in some states, Trump’s campaign insists it has built out a formidable ground game, despite the Republican nominee’s earlier reluctance to invest in it.

“People will be very surprised by our ground game on Nov. 8,” Trump tweeted last month. “We have an army of volunteers and people with GREAT SPIRIT!”

But interviews with GOP sources inside and out of the campaign’s fold suggest the nominee’s campaign is in fact still fleshing out its anemic ground operation while continuing to rely in large part on Republican National Committee resources.

The Trump team is actively looking to invest in a paid field program by hiring a firm such as Stampede Consulting, RealClearPolitics has learned. But no decision has been reached on where these resources would be deployed or through what firm, and time is running short. (Stampede advertises "turnkey grassroots" for camps that "don’t have time to start from scratch on a door-to-door field operation.")

One Republican strategist in a key battleground state said the Trump camp’s moves suggest “that they are worried about” the heft of their ground operations. “You can’t build an operation in 40 days, so they’re looking at how best to deploy resources,” the strategist said.

To date, ground operations have hardly been within the periphery of the campaign’s vision, much less its focal point. Republican strategists have described the campaign’s efforts in this sphere as close to zero, even as the general election has progressed.

The biggest push has come from Trump’s new campaign leadership team, including Kellyanne Conway, who is a pollster by trade.

“Mr. Trump is an unconventional candidate, but I have an appreciation for...conventional tactics," the campaign manager told CNN last month. "We've got to invest in the fundamentals."

As such, the campaign has begun to open offices in some key battleground states, while adding state and regional directors to the payroll. Advisers have also promoted efforts to register voters at Trump’s high-octane rallies across the country, in addition to cross-referencing rally attendees with state voter rolls in search of potential new voters to target and register.

But these tactics are only a fraction of the modern presidential campaign toolbox and pale in comparison to what Clinton’s campaign has built, with dozens of offices in crucial battlegrounds and a sophisticated analytics operation comprising 60 staff members .

“Somehow trying to act like this is groundbreaking stuff? It’s crazy,” said another Republican strategist with extensive national campaign experience. Trump’s operation is “literally so far behind, it’s not funny. They’ve taken us back 40 years.”

Where the campaign has until now shrugged off more traditional organizing on the ground, the Republican National Committee has stepped in to compensate. When asked to provide updated statistics regarding the Trump operation’s footprint in battleground states, a campaign spokesperson instead pointed to total GOP offices and staff in each state — emphasizing that Trump and the RNC have worked “hand-in-glove.”

Indeed, when the campaign opened its first North Carolina offices last month, it did so in conjunction with the RNC — meanwhile downplaying the importance of such offices altogether.

“Office numbers are a false metric and completely miss the point that, as we saw in the primary, Mr. Trump is not a typical politician,” the candidate’s North Carolina director, Jason Simmons, told the Charlotte News & Observer at the time.

Some Republicans predict that Trump’s celebrity and his resonant populist message will indeed sustain his candidacy without a traditional ground operation. But those factors are less powerful in harnessing absentee and early voting — both major components of the general election vote.

“That’s where organization matters,” said the national Republican strategist. As early vote estimates begin to come in, the strategist added, “we’re going to see numbers soon that are shocking.”

As the party’s nominee in 2012, Mitt Romney’s campaign invested well over $100 million in field organizing alone — and still fell short of President Obama. Using sophisticated micro-targeting, Romney’s camp sought to connect with low-propensity voters roughly 18 to 25 times before Election Day. For voters who often turn out during presidential elections but not in midterms, the target was 12 to 18 touches. High-propensity voters were contacted between five and eight times, a former adviser said.

Some Trump allies think their sweet spot will be among people who have not voted for many elections because they have grown so disenchanted with the political process. And the campaign likely has the capability to find these potential voters, paying $250,000 per month to Cambridge Analytica, a data firm developed by GOP mega-donor Robert Mercer. Ted Cruz used the operation during his presidential primary campaign; Trump’s campaign chairman, Steve Bannon, is an investor.

But without a full-fledged ground game, it is unclear how the campaign will reach these voters who might not otherwise be targeted by the party.

Meanwhile, the network of groups backed by the billionaire brothers Charles and David Koch has stepped in to fill the void on behalf of down-ballot candidates and turn out Republican voters across eight key states.

“We’ve been more focused on the field efforts and what is needed there to have a strong impact, particularly given the gap in field operations and infrastructure that can really turn out voters,” James Davis, executive vice president for strategic communications for Freedom Partners, told reporters last month.

In a conference call with reporters Thursday, Senate Majority Leader Harry Reid attributed Republicans’ strength in Nevada, another key battleground, to the influence of the network’s Latino-oriented outfit, LIBRE.

Back in Camp Hill, Pa., Maxine Hendricks was next up on Jeremy Baker’s canvassing list. As it turned out, she needed to be persuaded, but not by AFP’s canvassers: Hendricks knew she would not support Democratic nominee McGinty in the Senate contest, but she wasn’t so sure about Trump.

“If Trump wouldn’t be so wild, I think he’d be a good candidate,” Hendricks said. “He just talks off the top of his head, which doesn’t always work.”

As AFP state director Mumford walked on to the next house, she observed, “That’s a voter that needs to be persuaded!”

In a more predictable election, Hendricks “would be a voter that some people would assume you wouldn’t need to talk to,” Mumford added, noting Hendricks’ record of supporting Republicans. “But we’re able to, through the data, target people who are clearly undecided.”

Hendricks had received a piece of mail promoting Trump — but, as of yet, no phone calls or door knocks from either presidential campaign.