MILWAUKEE — Attendees of the Republican National Convention in Wisconsin have high hopes for Senator Vance as he prepares to deliver a keynote speech intended to introduce the first-term lawmaker to the nation. They say unity ought to be his message to those Americans who are frustrated by both parties. 

Mr. Vance, who has been a senator for just 18 months and never previously held elected office, may be one of the least-known vice presidential candidates in recent memory. According to a poll from the Associated Press released on Monday, 60 percent of voters said they did not know enough about Mr. Vance to form an opinion of him, compared to 9 percent who said the same about Vice President Harris. 

A delegate from Texas, Deana Abiassi, tells the Sun that Mr. Vance in his primetime introductory address should make it clear that he hopes to be a unifying second-in-command come January. “I’m super excited. I can’t wait to hear what he has to say,” she said. “His story is so compelling — a story of true American grit.”

What asked what she hoped to hear from the senator in his speech on Wednesday, Ms. Abiassi had one word: “Unity.”

“Unity, of course. Unity is going to be key,” she says. “I want him to talk a little bit more about his story so people can understand that we are a unique country, and what we offer is unique around the world. Somebody can come the most humble starts in life and can just rise up by their own virtue.”

A delegate from Massachusetts who also once served as a county sheriff, Thomas Hodgson, offered the same answer as Ms. Abiassi when asked what he wanted to hear from Mr. Vance. 

“I’m hoping for people feel a real sense of unity, for him to expound upon the importance of it,” Mr. Hodgson said. He added that Mr. Vance has to talk about his humble beginning and his rise to being the youngest major party vice presidential nominee in more than 70 years. 

Mr. Hodgson hopes he will “talk a little about his ability to overcome challenges early in life and create a success model for himself. … This is a guy who is pretty much self-made and I think most Americans can appreciate that.”

One more famous attendee, Roger Stone, tells the Sun that he his thrilled Mr. Vance was chosen, and says he has the opportunity to not only lay out a compelling vision for America’s future, but to carry the banner of Trumpism beyond the next four years. 

“I think it’s gonna be great. He’s gonna be totally supportive. The president demonstrated once against that he’s not an establishment Republican, that he’s not a neocon yearning for endless foreign war,” Mr. Stone says of the pick. “He’s the ideal running mate.”

When asked what he thought Mr. Vance needs to talk about in his speech on Thursday, Mr. Stone suggested he focus on his own evolution regarding President Trump. 

“My guess is that he will address his change of views on the president. People are allowed to change their minds. I think that’s important,” Mr. Stone says. 

Yet it isn’t just some nebulous “unity” message Mr. Vance needs to convey, attendees say. Mr. Hodgson, who was infamous for his tough-on-crime approach to illegal immigration in his home state of Massachusetts, says the border needs to be a key component of the Thursday address after historic numbers of migrants have come across the border. 

“The importance of moving immediately on immigration reform,” Mr. Hodgson said, listing his top concerns. He also noted that Mr. Vance ought to talk about kitchen table issues like the economy and inflation: “With his finance background, obviously the economy. People are hurting.” 

Beyond the Thursday speech and the ensuing spring to Election Day, conservatives at the convention believe Mr. Vance is a dyed-in-the-wool MAGA ally, and will be key to achieving Trump’s goals in a potential second term. 

The man who once ran the judicial nomination process for Senate Republicans and who now runs the conservative Article III project, Mike Davis, tells the Sun that Mr. Vance can not only be a great campaigner, but a great ally to the movement once he finishes setting up his office in the West Wing. 

“Senator Vance is great. J.D. Vance is the perfect pick,” Mr. Davis says. “It shows that President Trump is serious about governing and is serious about the America First agenda long after President Trump is out of office, so I’m thrilled.”

“He’s a serious, thoughtful leader and he’s ready to be President Trump’s wingman,” he added.