WASHINGTON — From the start, he was a central casting misfire — the dark artist slicing through the capital by electric scooter, a cloak-and-dagger digger better known to former colleagues for scratching his bare belly in plain office view.
In a past career, Glenn R. Simpson had been a reporter’s reporter, tenacious through two decades in journalism, often driving the Washington story of the day — congressional corruption, fund-raising shenanigans, sundry misbehavior — but never becoming it himself. “It’s not news when things go right,” he told a group of students in 1991, describing his craft. “When things go right, it’s boring.”
Mr. Simpson’s life has not been boring for some time now. It has, perhaps inevitably, become news.
As investigators circle President Trump’s administration over ties to Russia during the 2016 campaign, Mr. Simpson, a 53-year-old Wall Street Journal veteran-turned-master of high-dollar research, has arrived at the biggest story of either of his careers, lurching to the center of the Russia-tinged scandal that clouds the presidency.
Mr. Trump knows his work intimately. Mr. Simpson is the man behind an explosive dossier — produced at his firm, Fusion GPS, with a former British spy, Christopher Steele — outlining possible connections between the president, his associates and Russian officials.
For months, Mr. Simpson’s name has ricocheted across the halls of Congress and the airwaves of Fox News, becoming shorthand in conservative circles for purported investigatory overreach and counterconspiracies against the White House. Questions about his research have become central to Republican attempts to discredit not just Fusion but the very existence of inquiries into Mr. Trump, including the efforts of the special counsel, Robert S. Mueller III.
Republican leaders of the Senate Judiciary Committee have asked the Justice Department to investigate whether Mr. Steele, whom Mr. Simpson hired, lied to federal authorities about his contacts with journalists.
Mr. Simpson himself has been hauled before three congressional committees for some 20 hours of questions and answers, placing him among the most significant players in the Trump-Russia affair, if math is the metric.
“Uncooperative,” Senator Charles E. Grassley, Republican of Iowa, said of Mr. Simpson’s turn before the Judiciary Committee, which he leads.
“Very cooperative,” said Representative Adam B. Schiff of California, the top Democrat on the House Intelligence Committee, where Mr. Simpson also appeared.
Mr. Simpson can be both of these things — according to interviews with dozens of friends, colleagues and investigative targets — and a few more: brash, obsessive, occasionally paranoid, perhaps with cause.
The name of the firm, founded in 2010, was intended to represent a “fusion” of journalism and business intelligence. The “GPS” hinted aspirationally at a global reach.
In practice, Fusion’s task has often translated, roughly, to finding unsavory things about unsavory people, at the behest of not-especially-savory clients. The firm often represents corporations, hedge funds or law firms, providing a sort of public-records forensics that resembles journalism. It leans on its understanding of the news media, and its contacts among reporters, to elevate its clients and squeeze their adversaries.
In election years, political opposition research can consume more of Mr. Simpson’s time, with bipartisan demand.
The pay is good. And the targets are rich.
“He’s trying to figure out the puzzle,” said Stuart Karle, a friend and the former general counsel for The Journal. “That animates him. It always has.”