More than any other leading candidate, Biden is relying on big fundraising events to power his bid for the presidency, which makes these bundlers crucial to his success. Other big-name bundlers for Biden include New York venture capital and private equity investor Alan Patricof, and billionaire real estate broker George Marcus.

Biden is running for president on his longtime experience in public service, and his list of bundlers reflects the many high-powered connections he built over that time. Biden bundlers include current senators Pennsylvania Sen. Bob Casey and Delaware Sen. Chris Coons. Former White House chief of staff Erskine Bowles is a bundler for Biden, as is Dorothy McAuliffe, wife of former Virginia Gov. Terry McAuliffe.

A number of former ambassadors — who are often longtime bundlers and major political donors in their own right — are also helping Biden. They include Elizabeth Frawley Bagley, former U.S. Ambassador to Portugal; Denise Bauer, former U.S. Ambassador to Belgium; Anthony Gardner, former U.S. Ambassador to the European Union; and Mark Gilbert, former U.S. Ambassador to New Zealand, and more.

Biden has taken other measures to make his campaign transparent, including allowing press access to his fundraisers. But Buttigieg and Sen. Kamala Harris, before she dropped out, released lists of bundlers before the former vice president disclosed his list. Warren and Bernie Sanders, who do not hold closed-door fundraisers, say they aren’t releasing similar lists because they don’t have campaign bundlers.