Without Charlie Kirk, there might not be a Vice President JD Vance.

The influential conservative activist, who was tragically killed on Wednesday while delivering a speech at a college in Utah, played a crucial role in the early stages of Vance’s ascent in national politics.

Publicly, Kirk championed Vance as a promising Republican candidate — even when others within the Trump-dominated party were wary of Vance’s previous skepticism towards Trump.

Behind the scenes, Kirk acted as a connector, introducing Vance to key individuals who would support his journey from an outsider to an insider in the MAGA movement.

So when news of Kirk’s death landed Wednesday afternoon, it landed particularly hard on Vance.

In a last-minute move emphasizing their closeness, the vice president altered plans on Thursday, choosing to forgo a 9/11 memorial event in New York to visit Salt Lake City instead, where he and second lady Usha Vance intended to meet with Kirk’s relatives and acquaintances.

From there, Air Force Two was planned to transport Kirk’s casket, along with his family, to Phoenix, a source with knowledge of the arrangements told NBC News. Kirk’s political group, Turning Point USA, was headquartered there.

“Charlie was keen on ideas and always open to learning and reevaluating his views,” Vance expressed in a tribute he posted Wednesday night on X. “Like me, he had doubts about Donald Trump in 2016. Like me, he eventually recognized President Trump as the sole figure capable of shifting American politics from the globalism that prevailed throughout our lives. He learned from others when they were right, and when he was correct — which he often was — he showed generosity.”

Vance, 41, and Kirk, 31, shared common cause as representatives of a younger, Trump-inspired brand of conservatism that has thrived in a new media ecosystem populated by right-leaning podcasts. Trump’s outreach to young male voters and the podcast hosts they listen to — aided by allies such as Vance and Kirk — was seen as a significant piece of his winning 2024 strategy.

In his post Wednesday, Vance described Kirk as a key and influential figure in his 2022 Senate campaign in Ohio, where he started as an underdog in a crowded Republican primary. Kirk, he wrote, “was one of the first people I called” when weighing whether to run.

“We talked through everything, from the strategy to the fundraising to the grassroots of the movement he knew so well,” Vance added. “He introduced me to some of the people who would run my campaign and also to Donald Trump Jr.,” Trump’s eldest son, who “took a call from me because Charlie asked.”

It was the beginning of a nexus that, working alongside Vance’s political team in Ohio, would lead him to the White House.

Andrew Surabian, who would become one of Vance’s top political advisers, also linked up with Vance at Kirk’s urging.

“I’ll never forget that it was actually Charlie who first introduced me to JD,” Surabian recalled Thursday in a post on X.

“He texted me out of the blue one morning, at a time when I was considering which Ohio senate candidate to sign-on with, and said, ‘You need to meet JD Vance.’ I texted him back: ‘The Never-Trump guy!?’ He called me right away and insisted that JD was ‘one of us’ and had experienced a true conversion about Trump.”

Surabian was “on the phone with JD within the hour,” and they quickly hit it off and agreed to work together.

“Charlie excitedly told me I wouldn’t regret it,” Surabian wrote. “And he was certainly right about that.”

Surabian also was working closely with Trump Jr., who helped Vance smooth things over with his father. The elder Trump had been keenly aware of Vance’s past criticism. At a clear-the-air meeting that Trump Jr. helped arrange at Mar-a-Lago during the early days of the Senate campaign, there was “10 minutes of President Trump busting JD’s chops” before moving on to other topics, a person close to Vance told NBC News last year.

The effort paid off for Vance’s team. Trump endorsed and rallied for him in the closing weeks of the 2022 primary. In his victory speech, Vance thanked the Trumps and Surabian — and Kirk, who had campaigned alongside him in the final days of a tight race.

After Vance won the general election that fall, his friendships with Kirk and Trump Jr. blossomed. As speculation turned toward Trump’s selection of a running mate in 2024, both publicly promoted Vance as a strong contender at a time when Republicans like then-Sen. Marco Rubio of Florida and then-Gov. Doug Burgum of North Dakota were seen as safer choices. (Both ended up as members of Trump’s Cabinet after he won.)

“When I became the VP nominee — something Charlie advocated for both in public and private — Charlie was there for me,” Vance wrote Wednesday night on X. “I was so glad to be part of the president’s team, but candidly surprised by the effect it had on our family. Our kids, especially our oldest, struggled with the attention and the constant presence of the protective detail.”

“I felt this acute sense of guilt, that I had conscripted my kids into this life without getting their permission,” Vance added. “And Charlie was constantly calling and texting, checking on our family and offering guidance and prayers.”

Vance also credited Kirk with having a hand in his and Trump’s victory. He shared a photo Wednesday that showed him alongside Trump Jr., Surabian and Kirk after a campaign event days before the 2024 election.

Just after midnight on Inauguration Day, a tuxedo-clad Vance took the stage with Kirk at Turning Point’s inaugural ball following a performance from the Village People.

“I just want to say, from the bottom of my heart, thank you. Thank you to Charlie,” Vance said then.

In his Wednesday night post, Vance noted how he and Kirk had continued to stay in touch with others through a series of mutual group texts, some of them including “people at the very highest level of our government.”

“I was in a meeting in the West Wing when those group chats started lighting up with people telling Charlie they were praying for him,” Vance wrote. “And that’s how I learned the news that my friend had been shot. I prayed a lot over the next hour, as first good news and then bad trickled in.”

“God didn’t answer those prayers, and that’s OK,” Vance added. “He had other plans. And now that Charlie is in heaven, I’ll ask him to talk to [the] big man directly on behalf of his family, his friends, and the country he loved so dearly.”