President Donald Trump isn't easing up on his attempts to assert more control over the Federal Reserve. But Trump's decision to continue investigating former Fed Chairman Jerome Powell could make that goal even harder to achieve.

The Fed's inspector general released a report dated Tuesday finding that a multibillion-dollar renovation of the Fed's main building had been mismanaged, but it found no evidence of misconduct. Trump responded by making clear that he didn't consider the matter closed.

"This is Jerome Powell's fault, and he should be forced to resign, IMMEDIATELY! If he doesn't resign, he should be sued, at the highest level, by the United States Government, for either corruption or incompetence," Trump wrote in a post on TruthSocial.

Trump's insistence that Attorney General Todd Blanche take up the investigation essentially shut the door on whatever possibility existed that Powell resign his current post on the Fed's board of governors this year. Powell, whose term ends on Jan. 31, 2028, said in previous statements that he was waiting "for the investigation to be well and truly over with finality and transparency" before stepping down. The IG's report could have given the investigation finality, but Trump's post removed that possibility.

The Federal Reserve declined to comment.

Trump, a proponent of low interest rates, has long wanted to gain greater control of the Fed. He berated Powell publicly in recent years for keeping rates too high. The Fed increased rates by a quarter of a percentage point last month under Chairman Kevin Warsh, who succeeded Powell in May, but Trump laid blame at the feet of other board members, whom he said were making it difficult to ease monetary policy. In addition to trying to force Powell to resign, Trump has attempted to force out Fed Governor Lisa Cook for allegedly committing mortgage fraud, a charge she denies.

Any attempt by Trump to gain more spots on the Fed for his appointees could get more difficult after the November midterm elections. Recent polling gives Democrats a better-than-even shot of picking up enough seats to take control of the Senate, which would need to confirm successors to Powell or Cook. Bettors on prediction market Kalshi currently give Democrats a 62% chance of winning the Senate.

If Democrats win, Powell might feel more comfortable resigning in January, since Democrats could refuse to confirm a successor so long as the Justice Department is continuing an investigation of Powell, TD Cowen analyst Jaret Seiberg said in a research note on Thursday.

There is also precedent for an opposing party to withhold approval for any important nominations in an effort to keep the seat open for the next president.

When Fed governor Roger Ferguson's term expired in 2000, President Bill Clinton nominated him for a new 14-year term. Rather than confirm him, the Republican-controlled Senate held off on the vote, which Ferguson later said was because Republicans thought "we should wait until a new President came on board."

Ferguson stayed on the Fed as a holdover for well over a year and was renominated by President George W. Bush for a new term.

Powell said in April that he had "long planned to be retiring" and would probably be loath to stay through the end of his term in January 2028. But Trump's continued push for investigations could result in the former Fed chairman serving out his tenure.