The group had been preparing to host Kirk on the Philadelphia campus this semester. News of his death broke as they were organizing a 9/11 memorial.
One member from Utah had a sibling at the event and was following real-time updates as the tragedy unfolded.
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"He had a big appeal for a lot of people - whether they agreed with his beliefs or not - he was open to discussion and challenged young people," said Sunya Afrasiavi, political director of Penn College Republicans and a sophomore.
Kirk founded Turning Point USA at age 18 and quickly rose to prominence as a leading voice in GOP youth outreach. He expanded the organization's presence on college campuses and launched a popular podcast. His messaging, however, often drew controversy.
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"Nearly every university he went to drew a big crowd," Afrasiavi said.
William Pallan, finance director of the group and a Penn junior, said Kirk's approach to campus engagement was direct and inclusive.
"He sets up a tent on college campuses and says, 'Talk to me about any issue,'" Pallan said. "It was going to be something like that on Penn's campus this semester."
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Despite criticism from some quarters, Pallan said Kirk wasn't seen as divisive by many students.
"I don't think he's a divisive figure, a polarizing figure," he said.
In the wake of Kirk's death, the group reported a surge in membership applications and a renewed sense of unity.
"We're living in a time where both sides aren't coming together," Pallan said. "I think that pushes more people to the right."
Afrasiavi added that the moment should serve as a call to action.
"I think this should be a call not just for people on this campus, but to really go out and speak their beliefs," she said. "I don't think they should be frightened."