"I've never been more worried about a terrorist attack on our nation than I am right now, just not me saying it, it's all the people in the intelligence community," Graham said during a press conference. "The number of people that want to punish us for helping Israel is through the roof."
Graham underscored that the threat level at the US southern border is at an all-time high.
According to the Department of Homeland Security's Homeland Threat Assessment, US border agents in 2023 have encountered a growing number of migrants on the FBI's terrorist watchlist trying to illegally cross the US-Mexico border.
Graham stated the Biden administration is on track to see 10 million illegal crossings by migrants on the US southern border over the US president's four-year tenure.
On Wednesday, Senate Republicans blocked legislation to advance Biden's $110 billion supplemental bill over concerns it did not include "credible" measures to address the crisis on the US southern border.