Stewart, an outspoken advocate for veterans, was in DC to celebrate the Senate passing the Honoring Our PACT Act. But instead, 41 Republican senators voted against the bill, blocking it from advancing.
A furious Stewart turned toward the media to bash those who voted against it.
Posobiec and fellow ring-wing journalist Raheem Kassam approached Stewart with apparent questions regarding the bill, but the exchange seemingly turned sour with Stewart screaming in Posobiec's face.
The fiery exchange between Stewart and Posobiec was captured on video and posted to Twitter.
In the video, Stewart screamed as Posobiec he is a "troll" and "not in good faith".
Kassam posted the video to the social media platform saying he and Posobiec "asked some pretty ordinary questions, and Jon began screaming in our faces for about 10 minutes."
\u201cSo uh, @JackPosobiec and I went to speak with Jon Stewart outside the Capitol. Jack asked some pretty ordinary questions, and Jon began screaming in our faces for about 10 minutes. At one point he was nose to nose with me. I kept trying to calm him down.\u201d