Donald Trump’s election campaign manager has told of his ambition to build a data-gathering juggernaut based around the principle: “We want to know who you are and how you think.”

Brad Parscale, regarded by critics as an apologist for a uniquely dangerous and divisive US president, described to the Guardian a targeted advertising operation immensely more sophisticated than four years ago.

Every time someone donates to the Trump re-election campaign, buys some of its merchandise, registers on its mailing list, enters one of its competitions or attends one of the president’s rallies, there is an opportunity to hoover up an email address and other details that will come in useful later.

“The campaign is all about data collection,” Parscale said in a phone interview with the Guardian. “Every aspect of this campaign. Everything we do, if you go to a coalition event, you sign up for a thing, you touch it.

“If we touch you digitally, we want to know who you are and how you think and get you into our databases so that we can model off it and relearn and understand what’s happening.”

Parscale, who in 2016 was digital director of the insurgent Trump campaign, offered a metaphor. “Imagine it like it’s a gigantic highway but the only time people drive down it is when there’s a big event. Say you live on the north side, all you do is go to the grocery store but every once in a while there’s a huge football game and that’s the time you drive downtown.

“Well, we want to run a billboard at that time for my best sporting thing when we know all the sports people are coming down the street. It’s the same principle, right? And so what we want to do is blow things up when we know the people are on the highway.”

Parscale’s efforts, including ads that make misleading claims and clickbait that exploits voters’ grievances, pose a hefty challenge to Democrats.

Michael Slaby, who was Barack Obama campaign’s chief technology officer in 2008 and chief integration and innovation officer in 2012, recently warned the left had suffered “over-confidence” while Trump’s social media strategy forged ahead.

Asked if he believes Democrats will try to assemble a similar model, Parscale replied: “We have no idea what they’re going to build. That’s up to you guys to go figure out. We do have an advantage in time. The president was extremely smart the day after the election to say why take our foot off the gas?

“Election day 2016 wasn’t the end of the fight. It was the start of the fight. And let’s just keep going. Let’s keep fundraising. Let’s keep building. This is a fight for eight years. This isn’t a fight just for a few months.”

At 44 years of age, and 6ft 8in in height, the bearded Parscale, who is from San Antonio, Texas, has become an improbable and recognizable figure at campaign rallies, warming up the crowd before Trump’s arrival. He said he has three objectives there.

“I’m the first one that’s getting up there and saying, we’re almost there, hang with us. It takes hours to get all those people through all the mags [metal detector]. Two, is to rah rah them a little bit, get them pumped up, help them understand the importance of their state and give them just a little bit of boost right before.

“And then lastly is to get the data so I make them try to all memorise 88022. I make them chant it and memorise it and my goal is to make everybody in America know that number 88022. There is no better methodology to contact voters and raise money than cellphone text messaging.”

For all the tools and screens of the digital age, it was clear in 2016 that Trump’s rallies carried an old-fashioned power of live theatre. People in long-forgotten small towns queued for hours to see him, saying they were grateful to be remembered at last. He encouraged them to tell their friends and neighbors about the “once in a lifetime” experience.

Yet the crowds at Trump rallies are overwhelmingly white. The president has sometimes fired them up with racist rhetoric towards immigrants or Ilhan Omar, one of the first Muslim women in Congress. He stands accused of deepening divisions in what some have called a cold civil war. Parscale denies the premise and blames the media.

“The news and the media has one job: to sensationalise everything to make money. They’re not there to give us news. They’re there to make money and they have stock prices now and they have ratings reviews and they have everything and telling that America is boring doesn’t sell anything. People turn off the news.”

But is Trump racist? “Well, 100% he’s not a racist. It’s upsetting, obviously, when someone tells you something that is demeaning and almost vulgar to say about you.”

Last month the president was impeached by the House of Representatives for abuse of power and obstruction of Congress after pressuring Ukraine to investigate Joe Biden, one of his 2020 election rivals. His Senate trial is currently under way, putting his misconduct under a microscope. But Parscale does not believe it will inflict lasting political damage.

“I’ll tell you that nothing that’s occurred over the last couple of months has driven down his numbers at all. According to the numbers, he’s actually gone up from this and his approval numbers have [too].”