Donald Trump has lost a go-to ally in the Senate after the death of Lindsey Graham, with senior White House aides and other Republicans — and even some Democrats — saying the late senator had become a crucial part of the president’s legislative efforts.

The 71-year-old Budget Committee chairman and national security hawk was a fierce Trump critic in 2015, as they both sought the GOP presidential nomination. But he quickly morphed into one of Trump’s closest congressional allies after the 45th president took office, with Trump on Sunday declaring in a television interview that he saw the South Carolina Republican, who Washington, D.C.’s medical examiner said preliminarily died of aortic dissection, “like a member of the family.”

“It’s very tough, actually. It’s amazing. … He was such an advocate,” Trump told NBC’s “Meet the Press” program on Sunday. “He had a unique ability. He was able to deal with Democrats and Repub[licans]. If I had a problem, a real problem, I wouldn’t often ask. But if I had a problem with a Democrat, he could work it out. He was … a great politician, actually.”

Stephen Miller, White House deputy chief of staff for domestic policy, in a X post described the late senator as instrumental in securing the votes of some Senate GOP skeptics last year as Trump, administration officials and allies like Graham worked on what became the party’s sweeping tax and spending law.