BREAKING OVERNIGHT — “Russian Security Service Detains Wall Street Journal Reporter,” by WSJ’s Daniel Michaels: “The Federal Security Service said Thursday it had detained Evan Gershkovich, a U.S. citizen, in the eastern city of Yekaterinburg. The FSB said in a statement that Mr. Gershkovich, ‘acting on the instructions of the American side, collected information constituting a state secret about the activities of one of the enterprises of the Russian military-industrial complex.’ … ‘The Wall Street Journal is deeply concerned for the safety of Mr. Gershkovich,’ the Journal said in a statement. Mr. Gershkovich reports on Russia as part of the Journal’s Moscow bureau.” “Trump’s lead grows in GOP primary race, now over 50% support,” by Fox News’ Victoria Balara: “The survey, released Wednesday, finds [Donald] Trump has doubled his lead since February and is up by 30 points over Ron DeSantis (54%-24%). Last month, he was up by 15 (43%-28%). No one else hits double digits.” See the poll Our colleagues Hailey Fuchs, Clothilde Goujard and Daniel Lippman have a big investigation up this morning into the transatlantic political influence machine that TikTok put together as it battles efforts to regulate or ban the platform because of ties to China. Read the full story: “How TikTok built a ‘team of Avengers’ to fight for its life” And today, VP Kamala Harris is in Tanzania, where she’ll meet with President Samia Suluhu Hassan, the country’s first female head of state. But the bulk of Harris’ Africa trip is now over. And from the administration’s point of view, it was a success — but perhaps not for the reasons you think. Subscribe to the POLITICO Playbook newsletter Raghu Manavalan is the host and senior editor of POLITICO's Playbook Daily Briefing.Jenny Ament is the executive producer of POLITICO Audio.