‘TikTok Grandma’ Who Helped Tank Trump Rally Now Works for Biden

Last weekend, Mary Jo Laupp was enjoying a quiet night at a birthday party for her granddaughter — until she picked up her phone and her world flipped upside down.

A TikTok video she had made urging people to reserve tickets to President Trump’s June 20 rally in Tulsa, Okla. — and then not show up — had gone viral. Rally attendance had turned out to be far lower than billed by the Trump campaign, and TikTok teens and Korean pop music fans were taking a victory lap online. Ms. Laupp’s phone was blowing up with calls, messages and notifications.

Now Ms. Laupp, 51, who has become known as “TikTok Grandma,” has been recruited by the Biden Digital Coalition, a grass-roots organization, to put her TikTok skills to work supporting the presidential campaign of Joseph R. Biden Jr.

The coalition, made up of about 100 people — many of whom are alumni of other Democratic presidential campaigns — works to amplify pro-Biden messages and build engagement on social media. While it is not part of Mr. Biden’s campaign, it is in contact with Biden staff members. Coalition members, who are all volunteers, said they brought on Ms. Laupp for her ability to turn a viral moment into a call to action.