By Justin Worland
August 16, 2015

Stephen Colbert has been doing everything from hanging out with Mitt Romney to appearing on public access television to promote next month’s launch of The Late Show with Stephen Colbert.

On Sunday, he rallied about 600 fans in New York’s Union Square for what is thought to be his latest promo. Based on social media accounts, the event featured Colbert speaking to the crowd over a megaphone from the back of a truck and the fans holding balloons in the air and cheering.

Colbert’s Late Show will premiere on Sept. 8. Jeb Bush and George Clooney will be his first guests.

Write to Justin Worland at justin.worland@time.com.

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