Long before Stephen Miran was tapped by President Trump to join the Federal Reserve, the former hedge fund strategist proposed profound changes to the world’s most powerful central bank.

Among the most noteworthy ones in a detailed memo that he helped write in 2024 urged an end to the “revolving door between the executive branch and the Fed” on the basis that it was “critical to reducing the incentives for officials to act in the short-term political interests of the president.”

Mr. Miran, who most recently served as one of Mr. Trump’s top economic advisers, now finds himself on that exact journey. On Thursday, he will testify in front of the Senate Banking Committee as lawmakers consider whether to confirm him as the newest member of the Fed’s Board of Governors.

Mr. Miran’s hearing was hastily scheduled to keep open the possibility that he could be in place before the Fed’s next meeting on Sept. 16-17. He was selected to fill a temporary position in August, after Mr. Trump unexpectedly got an opportunity to name a replacement for Adriana Kugler, a Fed governor who stepped down from her post five months before her term ended.

The hearing will offer lawmakers their best opportunity yet to dig into the Trump administration’s plans to overhaul the central bank amid a relentless pressure campaign from the president, who wants the Fed to slash interest rates.

Mr. Miran sought to get ahead of those inquiries, expressing his intent to uphold the political independence of the Fed in opening remarks that he plans to deliver to lawmakers on Thursday. Those remarks, released on Wednesday, stressed that he would base policy decisions only on his “analysis of the macroeconomy and what’s best for its long-term stewardship” rather than hew to advice from “outsiders.”