An airplane decorated in tribute to Donald Trump, to test independent border-watching tech. (Glenn Spencer/American Border Patrol)

Years ago, an engineer named Glenn Spencer bought a little compound on the U.S.-Mexico border from an Arizona farmer who was tired of the drug cartels' shoot-outs spilling onto his land. It became the home base of American Border Patrol, a company that would develop radars, seismic sensors, and drones to police the border -- a job Americans weren't doing, to coin a phrase.

Spencer, like so many immigration hawks, suffered through years of political disappointment, until he finally found salvation in Donald Trump. For the first time since 1996, he thought, a credible candidate for the presidency was talking about the threats coming across the border. Last month, Spencer appeared on former Arizona Rep. J.D. Hayworth's NewsMax show and invited Trump to personally watch the test of his new triple-threat radar/sonar/seismic detection tech, designed to catch anything unusual crossing the border. It could supplement the border fence that obviously, also, needed to be built.

"Those that will come can see firsthand the type of technology that is needed to see if the border is secure," said Spencer.

Trump could not make it, but according to Spencer, he assigned someone to watch. That inspired Spencer to paint the plane used to test the technology: "GO TRUMP." Trump's aide failed to show, but Spencer's enthusiasm was undimmed. His SEIDARM was detecting movement 500 feet across the border.

"I have not decided to officially back Trump -- there is another in the pack that I prefer -- however, I encourage him to continue on his chosen path," said Spencer. "As he does, he will discover political treasures that the does not now realize are there to be found. Attempts by Pat Buchanan and a few others to ride a wave of anti-illegal immigration fell short, but now the wave may be large enough, and Trump’s board good enough, to take him all the way to shore."

Trump's campaign, which was sent Spencer's research by The Washington Post, did not immediately say what he thought of the test. But few campaigns would try to win over Glenn Spencer. He is a regular target of the Southern Poverty Law Center, which has labeled him a "vitriolic Mexican basher," and he's attended meetings put on by the white nationalist publication American Renaissance. He's home-brewed border technology even as he's had to explain away why a Minuteman activist-turned-murder suspect, Shawna Forde, wound up on his property.  ("I still don’t know why Shawna Forde suddenly appeared at my front door, but I am sorry she did," he wrote in 2009.)

Spencer -- no surprise here -- has rejected the "white nationalist" branding. In the 1990s, when he got active in California's border control movement, he was fighting side by side with black people. "Nationalist, yes; white only, no," said Spencer. "Trump’s call for an end to illegal immigration will resonate with the black community -- and legal Hispanics -- who see their job opportunities increasing under his administration."

Still, Spencer's embrace of Trump is the latest example of a person that had stalked the fringes of politics seeing a chance to Make America Great Again. In this week's issue of the New Yorker, Evan Osnos profiles a number of white nationalists who see Trump's rise as the validation of their work. "I’m sure he would repudiate any association with people like me," American Renaissance's Jared Taylor tells Osnos, "but his support comes from people who are more like me than he might like to admit."