Mapping the full Russian propaganda effort is important. Yet investigators in the House, Senate, and special counsel Robert Mueller’s office are equally focused on a more explosive question: did any Americans help target the memes and fake news to crucial swing districts and wavering voter demographics? “By Americans, you mean, like, the Trump campaign?” a source close to one of the investigations said with a dark laugh. Indeed: probers are intrigued by the role of Jared Kushner, the now-president’s son-in-law, who eagerly took credit for crafting the Trump campaign’s online efforts in a rare interview right after the 2016 election. “I called somebody who works for one of the technology companies that I work with, and I had them give me a tutorial on how to use Facebook micro-targeting,” Kushner told Steven Bertoni of Forbes. “We brought in Cambridge Analytica. I called some of my friends from Silicon Valley who were some of the best digital marketers in the world. And I asked them how to scale this stuff . . . We basically had to build a $400 million operation with 1,500 people operating in 50 states, in five months to then be taken apart. We started really from scratch.”

Kushner’s chat with Forbes has provided a veritable bakery’s worth of investigatory bread crumbs to follow. Brad Parscale, who Kushner hired to run the campaign’s San Antonio-based Internet operation, has agreed to be interviewed by the House Intelligence Committee.