In a surprising twist of political dynamics, JD Vance, former critic of Donald Trump, is set to introduce himself to a national audience on Wednesday as he addresses the Republican National Convention. The 39-year-old Ohio senator, who was once a severe critic of Trump, has transformed into an aggressive defender and is now positioned as a potential leader of the former president's political movement.

Vance's keynote speech at the convention will be his first as the Republican vice-presidential nominee, despite being a relative political unknown until recently. As the first millennial to join a major party ticket, Vance's arrival comes at a time when concerns about the age of the men leading the presidential race, Trump (78) and President Joe Biden (81), have been at the forefront of voters' minds.

Expected to lean into his compelling biography, Vance grew up in humble circumstances in Kentucky and Ohio before becoming a Marine, an Ivy League graduate, a successful businessman, and a best-selling author with his memoir, "Hillbilly Elegy." The book, published in 2016, shed light on the cultural forces that played a significant role in Trump's rise to the White House.

However, it is worth noting that Vance's journey to becoming an ally of Trump was marked by a dramatic shift in his opinion. During interviews in the past, Vance publicly criticized Trump, referring to him as "noxious" and even compared him to "America's Hitler." Yet, over time, Vance began to warm up to the former president, particularly as he sought the U.S. Senate seat in 2022. Vance eventually won Trump's endorsement, which played a crucial role in securing the party's nomination for the Ohio Senate seat.

Since accepting Trump's offer to join the ticket, Vance has become an outspoken defender of the former president, sparring with journalists, campaigning on his behalf, and appearing alongside him during his trial in New York.

In a recent interview with Fox News Channel, Vance explained his change of heart, praising Trump as a great president who delivered peace and prosperity. This acknowledgment of Trump's accomplishments has further solidified Vance's alignment with the former president's vision and policies.

As Vance takes center stage at the convention, Donald Trump Jr., a close friend of Vance, is also expected to speak. The Republican Party aims to emphasize the theme of American global strength throughout the event.

Vance's role within the RNC and his willingness to publicly support Trump mark a significant shift in his political stance. His journey from critic to ally reflects the growing influence of Trump's political movement and the reshaping of the Republican Party. All eyes will be on Vance as he lays out his vision for the future of the party during his highly anticipated speech at the Republican National Convention.