Americans for Prosperity field director Jeremy Baker speaks with Laura Ocker while canvassing on June 16 in King of Prussia, Pa. (Mark Makela for The Washington Post)

Jeremy Baker, a field director for the Americans for Prosperity conservative group, was looping through this neatly manicured Philadelphia suburb on a mission last week to make the case against Democratic Senate contender Katie McGinty.

But nearly every voter had someone else on their minds: Donald Trump.

“I thought you were going to ask about the presidential campaign,” said Laura Ocker, a registered Republican in her 50s who quickly assured Baker that she was voting for GOP Sen. Patrick J. Toomey. “That’s a lot harder.”

Baker let the comment pass. The 1,200 people employed by AFP and other groups in the Koch brothers’ political network are mute when it comes to Trump, the presumptive Republican presidential nominee.

It’s an odd situation for the powerful conservative operation, which was expected to harness its sprawling machinery on behalf of this year’s Republican nominee. But Trump’s incendiary statements and inconsistent policy stances have dismayed Charles Koch, the billionaire industrialist who leads the network and who has said he is unlikely to support the real estate mogul. Instead, Koch-backed groups are training their resources on boosting vulnerable Republican Senate candidates.

Americans for Prosperity field director Jeremy Baker uses an iPhone with targeted voter information and a map to canvass in King of Prussia, Pa. (Mark Makela for The Washington Post)

Last week, AFP launched ground operations on behalf of GOP incumbents in Pennsylvania, Ohio and Wisconsin — the earliest the group has ever begun making explicit political appeals in the field.

But just a few hours into the effort, it was apparent how difficult it will be to avoid Trump’s outsize presence in the campaign. And it was clear that even if the Koch network stays out of the presidential race, it could still end up being one of Trump’s best assets.

The Koch operation’s field teams are gathering reams of information on voters in key battleground states, intelligence that filters back to the Republican National Committee and GOP candidates through a data-sharing agreement. Even more valuable is the early organizing push by the network’s robust ground force, which far outstrips Trump’s meager field operation and could help prod ambivalent voters to the polls.

That includes voters such as police officer Joe Glasgow, who was just waking up after working a night shift when Baker stopped by his home on a drizzly morning to discuss the Senate race.

Glasgow assured the AFP organizer that he liked Toomey, then offered, unbidden: “I’m not a big Trump guy.” But he will probably end up voting for the GOP candidate, he told a reporter later, adding, “I despise Hillary Clinton.”

Over the next three days, AFP’s state organizers, and volunteers and staffers from around the country, blitzed 375,000 independent and Republican-leaning voters in Pennsylvania and 434,000 in Wisconsin with porch visits and phone calls. The network’s top Senate priorities also include races in Nevada and probably Florida — all swing states that will be pivotal in the White House contest.

Beth Anne Mumford, Pennsylvania state director for Americans for Prosperity, addresses volunteers and staffers before canvassing. (Mark Makela for The Washington Post)

Corey Lewandowski, who left his job as Trump’s campaign manager Monday, said last week, “I would think any effort to turn out Republican and right-leaning voters would benefit Mr. Trump.”

Koch Industries general counsel Mark Holden said the organization’s current focus is simply on promoting Senate candidates. He declined to discuss a private meeting he had last week with Trump campaign officials at their request. But he said network officials have yet to see a presidential candidate who shares their commitment to limited government and is not engaging in “mudslinging.”

“Our priorities are always the issues and the framework for a free society,” said Holden, who serves on the board of Freedom Partners, the network’s main funding arm. “This cycle, we’ve looked at where we have candidates that match up with that and the policies we care about.”

Charles Koch, his brother David and their conservative brethren are on track to spend $750 million this cycle through the network, with roughly a third — $250 million — financing the policy and political campaigns of groups such as AFP, Freedom Partners Action Fund, Concerned Veterans for America, the LIBRE Initiative and Generation Opportunity, officials said.

That’s less than the $889 million spending goal that the network initially set at the beginning of the two-year election cycle, in part because of the network’s decision to stay out of the presidential race. Holden said the original figure was more of “wish-list number” that was adjusted “to reflect the reality of where we are now.”

Even with a smaller footprint, the Koch operation is viewed as singular on both sides of the aisle. Most of the money flows into an alliance of nonprofit groups, allowing the organization to exert tremendous influence without revealing its donors.

“I think it’s the most powerful machinery that has ever been assembled to execute at the state level,” said Rob Stein, a Democratic strategist who has studied conservative political networks. “They have created a virtual political party.”

Already, the network has spent $15.4 million on ads in Senate races and has reserved $30 million more for August and September. But much of the money in this cycle is going into expanding its ground force and intensifying a data-analytics effort conducted by a Freedom Partners-backed company called i360, which maintains profiles of 194 million voters.

“After the 2012 election, we realized our capabilities weren’t where they needed to be,” Holden said. “We really upped our game and our investment in the permanent infrastructure.”

The central database maintained by i360 includes information gleaned from tens of millions of voter contacts made by Koch network groups, along with data from numerous Republican campaigns that have hired the company and agreed to share the data they collected in the field. In this election cycle, i360 has more than 200 GOP campaigns and state parties as clients, officials said.

That reach has allowed the company to deepen its portraits of each voter. Currently, i360 has at least 400 to 500 pieces of data — and in some cases thousands of pieces — about each individual. The firm’s president, Michael Palmer, said a regular flow of new information makes it possible to constantly refresh and refine voter profiles.

“Voters’ minds change,” Palmer said. “Making sure that data is updated in real time, or at least on a daily basis, so it’s actionable to the field is key to what we’ve built over the last few years.”

The company spent most of last year engaged in data-science experiments, working to better identify not only which voters need persuasion but also which messages are most likely to move them, Palmer said. That information feeds directly back to volunteers on the ground, who are automatically served up scripts on their iPads tailored to the homes they are contacting.

“If you go up to someone even remotely interested in health care and you say ‘Obamacare’ in the first breath, they are almost always going to talk to you,” said Tim Phillips, AFP’s president.

The Koch network is also pouring resources into tests that measure the effectiveness of various political tactics. In one experiment in Ohio in April, the organization found that waging an intense door-knocking and phone-call program over one weekend was comparable to a three-week television ad buy in lowering Democratic Senate candidate and former governor Ted Strickland’s favorability ratings.

That’s one reason AFP decided to launch an early effort on the ground this month directly advocating for specific candidates, rather than the softer issue-based campaigns it typically runs until closer to Election Day. As a nonprofit “social welfare” organization, the group is permitted to spend less than half its money on such political activity.

“You guys get a sneak preview of what we’re going to be doing pretty aggressively over the next few months,” AFP’s Pennsylvania state director, Beth Anne Mumford, told a group of volunteers gathered in a small office in a King of Prussia office park last Thursday.

Mumford and a group headed out into the wet morning with piles of slick brochures featuring a picture of a man holding a fistful of cash over the words, “Pennsylvanians Cannot Afford Katie McGinty In The Senate.”

Most of the voters they encountered, like Ocker, were already solidly committed to back Toomey. But she sighed heavily when a reporter asked about her views on Trump.

“I still believe in the Republican Party, but I have mixed feelings about the candidate,” Ocker said. “He doesn’t stick to one viewpoint, which scares me.”

So how does she plan to vote? Will she sit out the presidential race?

Ocker paused. “I think I probably will vote Republican.”