RNC 2024 Day 3 updates: JD Vance touts working class roots in debut as VP nominee

The conventional wisdom is that presidential candidates should pick running mates who will give them a boost in a key swing state. But Trump didn't do that: Vance is from Ohio, a state that used to be pivotal in presidential elections but has now become pretty reliably Republican. (Trump won it by 8 points in 2020 even as Biden was winning nationwide by a healthy margin.)

Was that a missed opportunity for Trump? Probably not: It turns out that vice-presidential candidates barely matter. Historically, they have been worth about 1 additional percentage point in their home state -- if that -- and don't make a difference in other states. So while Vance might be worth a few extra votes in Ohio, his selection is unlikely to move the needle even in neighboring states such as Pennsylvania and Michigan and probably won't affect the election outcome.

-538's Nathaniel Rakich

Multiple Republican senators chased down U.S. Secret Service Director Kimberly Cheatle after they spotted her at the RNC on Wednesday.

Tennessee Sen. Marsha Blackburn was one of the senators and shared a video of the confrontation on her X page, where she accused Cheatle of "stonewalling" them as she refused to respond to their repeated jeers.

"This was an assassination -- you owe the people answers, you owe President Trump answers," Blackburn can be heard saying in the video.

Multiple sources, who verified the authenticity of the video, told ABC News that the Secret Service director was on the suite level of the convention hall.

Blackburn was joined by Sens. John Barrasso, James Lankford and Kevin Cramer in confronting the director at the convention. Their move is unprecedented.

-ABC News' Allison Pecorin and Katherine Faulders

Kai Trump, the eldest granddaughter of Trump, took to the RNC to, as she put it, to "share the side of my grandpa that people don't often see."

"He gives us candy and soda when our parents are not looking," she said, as Trump looked attentively on smiling.

"He calls me during the middle of the school day to ask how my golf game is going and tells me all about his. But then I have to remind him that I'm in school and I will have to call him back later," she said. "When we play golf together, if I'm not on his team, he will try to get inside of my head. And he is always surprised that I don't let him get to me. But I have to remind him, I'm a Trump, too."

Kai, 17, the daughter of Donald Trump Jr., addressed Trump's legal troubles, saying, "Even when he is going through all of these court cases, he always asks me how I'm doing."

She said she was "shocked" to hear about Saturday's assassination attempt.

"It was heartbreaking that someone would do that to another person," she said. "A lot of people have put my grandpa through hell and he's still standing. Grandpa, you are such an inspiration and I love you."

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Trump's grandchild, Kai Trump, addresses RNC

Kai Trump, the eldest granddaughter of Trump, took to the RNC to, as she put it, "share the side of my grandpa that people don't often see."

ABCNews.com

After Trump’s eldest granddaughter, Kai Trump, spoke at the RNC, her father Donald Trump Jr. commended her for speaking in such a large crowd.

“Kai 2040,” someone yelled.

“Thank you, sir,” Trump Jr. responded with a laugh.