Before Glenn Youngkin was a culture warrior who cheered the demise of diversity, equity and inclusion programs, he was a financial executive who worried about a lack of diversity in his field.

“One of the clear challenges in the financial sector broadly is both race and gender diversity,” Mr. Youngkin said in a 2018 interview with Bloomberg Markets, soon after becoming a co-chief executive at the Carlyle Group, a private equity firm.

His company, he noted approvingly, had worked for years to address disparities in representation.

“The second we stepped into this role, we emphasized that this approach was not only going to continue,” he added, “but it was going to be one of our key priorities.”

Seven years later, Mr. Youngkin is the Republican governor of Virginia, an ambitious conservative who harnessed concerns about classroom instruction on race into political power, and who has energetically embraced President Trump’s hostility to D.E.I. initiatives.

“D.E.I. is dead in Virginia,” he declared recently.

In tone and emphasis, his transformation has been striking, and more drastic than commonly understood, according to interviews with half a dozen people who worked with Mr. Youngkin during his time leading Carlyle, as well as a review of company statements, official filings and other documentation from that time.

But in many ways, the evolution of Mr. Youngkin — who some Republicans hope will run for president — reflects the ever more chameleonic nature of his party at the dawn of a second Trump era.