Obama, like most presidents in the age of television, often gives speeches against a human backdrop. The people who join him onstage aren’t just a collection of regular folks, even when they’re billed as such: They’re carefully sourced, selected, and positioned by the White House for maximum messaging impact.

Take some of the president’s recent speeches. In April, Obama gave a speech on raising taxes on millionaires and was surrounded by wealthy people who want their taxes raised. In June, he gave a speech on keeping student-loan interest rates low and was surrounded by college kids. On Monday, he gave a speech on keeping middle-class taxes low and was surrounded by middle-class taxpayers.

To find human props, the White House reaches out to local and national groups who care about the relevant issue, according to the White House and others familiar with the process. Social media, past contacts, and personal connections also help the White House find attendees.