Vice Presidential Nominee Senator J.D. Vance (R-OH) speaks on Day 3 of the Republican National Convention (RNC), at the Fiserv Forum in Milwaukee, Wisconsin, U.S., July 17, 2024. / REUTERS/Mike Segar

MILWAUKEE (Reuters) -Donald Trump's vice presidential running mate, U.S. Senator J.D. Vance, presented himself to the nation on Wednesday night as the son of a neglected industrial Ohio town who will fight for the working class if elected in November.

In chronicling his hardscrabble journey from a difficult childhood to the U.S. Marines, Yale Law School, venture capitalism and the U.S. Senate, Vance, 39, introduced himself to Americans while using his story to argue he understands their everyday struggles.

"I grew up in Middletown, Ohio, a small town where people spoke their minds, built with their hands and loved their God, their family, their community and their country with their whole hearts," Vance said, formally accepting the party's 2024 nomination at the Republican National Convention in Milwaukee. "But it was also a place that had been cast aside and forgotten by America's ruling class in Washington."

He accused "career politicians" like President Joe Biden - who Vance noted has been in politics longer than he has been alive - of destroying communities like his with ill-fated trade policies and foreign wars.

"President Trump's vision is so simple and yet so powerful," he said. "We're done, ladies and gentlemen, catering to Wall Street. We'll commit to the working man."

In a sign of his potential value to the ticket, Vance also appealed to the working and middle classes in Michigan, Pennsylvania and Wisconsin specifically - three Rust Belt swing states likely to decide the Nov. 5 election.

Vance's prime-time debut, less than two years after assuming his first public office, capped a meteoric rise that coincided with his transformation from a fierce Trump detractor to one of his most devoted defenders. He is one of several high-profile Republicans, such as U.S. Senators Ted Cruz and Marco Rubio, whose reversals from critics to loyalists underscore Trump's takeover of the party.

For Trump's political opponents, his hold on the party portends a darker moment if he follows through on promises to vastly expand the power of the presidency, exact revenge on his enemies and threaten longstanding democratic institutions.

Author of the bestselling memoir "Hillbilly Elegy ," Vance has helped to shape Trump's populist instincts into a policy agenda that would pull the U.S. back from its dominant role in global affairs. As the first millennial on a major party's ticket, he is positioned to carry Trump's Make America Great Again movement beyond a potential second Trump term.

His speech embraced many of Trumpism's core tenets, promising to prioritize domestic manufacturing over Chinese imports and warning allies they would no longer get "free rides" in securing world peace.

Vance has opposed military aid for Ukraine and defended Trump's attempts to overturn his 2020 election loss to Biden. He has argued the government must do more to assist the working class by restricting imports, raising the minimum wage and cracking down on corporate largesse. Those positions, at odds with the Republican Party's traditional pro-business stance, nonetheless track Trump's program closely.

Democrats have already gone on the offensive around Vance's strict anti-abortion views. In a statement on Wednesday, the Biden campaign said Vance would advance "an agenda that puts extremism and the ultra wealthy over our democracy."

Biden, 81, was forced off the campaign trail on July 17 after testing positive for COVID-19, compounding his woes after three tumultuous weeks struggling to reassure panicked Democrats that he can still defeat Trump, 78, following an anemic debate performance on June 27.

Trump, his right ear still bandaged after it was grazed by a would-be assassin's bullet at a July 13 rally in Pennsylvania, walked into the convention to roars and the sound of James Brown's "It's a Man's Man's Man's World" playing throughout the arena. Trump will close the convention with a July 19 speech.

In his speech Vance described his grandmother, "Mamaw," who raised him while his mother struggled with addiction, and acknowledged his mother Beverly, who was on hand to watch him speak.

"I am proud to say that tonight my mom is here, 10 years clean and sober," Vance said. "I love you, Mom."

A visibly moved Beverly Vance mouthed, "I love you, J.D.," while delegates gave her a standing ovation.

HARD-HITTING SPEECHES

The evening featured a hard-hitting, emotional video in which families of soldiers killed during the 2021 U.S. troop withdrawal from Afghanistan blamed Biden for their deaths. The relatives then took the stage and voiced their anger, with some in the audience wiping away tears.

Several speakers leveled aggressive and sometimes baseless attacks against the Biden administration. The heated tone contradicted the message of national unity Trump had promised to deliver after the attempt on his life at July 13's rally.

Former Trump White House official Peter Navarro, who was released from prison earlier in the day after serving four months for contempt of Congress, received a huge ovation as he took the stage.

Navarro, who was convicted for refusing to comply with a subpoena from the committee investigating the Jan. 6, 2021, attack at the U.S. Capitol by Trump supporters, said he, like Trump, was a victim of Biden's "Department of Injustice."

Trump has frequently claimed, without evidence, that his four indictments since leaving office were part of a Democratic conspiracy to prevent his election.

Others focused on Biden's border policies, a favorite target for Trump.

Tom Homan, who served as acting director of Immigration and Customs Enforcement under Trump, said Biden was the first president in history to "unsecure" the border.

"This isn't a choice," he said. "It's national suicide."

As he spoke, delegates waved signs that read, "Mass Deportation Now!"

While border crossings reached record highs during Biden's tenure, arrests dropped sharply in June after the president implemented a broad asylum ban.

Trump has pledged to launch the largest deportation effort of illegal immigrants in U.S. history.