New Delhi, Sept. 18 -- One day before his assassination, conservative activist Charlie Kirk texted Homeland Security Secretary Kristi Noem urging accountability for local officials resisting federal immigration policy.

"The last message he had texted me was the day before he passed away, and it said, 'We have to hold these mayors and local officials accountable for what they're doing,'" Noem said on The New York Post's podcast.

Noem, 53, told columnist Miranda Devine that she did not see the message until after Kirk was killed during his Sept. 10 speaking event at Utah Valley University.

"Charlie, he was incredible. It still makes me so sad that it's hard to talk about," she said. "I will always feel bad that I didn't respond because I...