The Federal Reserve is expected to raise interest rates by a quarter of a percentage point on Wednesday, lifting them from 3.5% to 3.75% as inflation remains above the central bank’s 2% target for five years. The increase would be the first since July 2023 and would put Kevin M. Warsh at odds with President Trump before midterm elections that will determine whether Republicans retain control of Congress. Trump has repeatedly pressed the Federal Reserve to reduce borrowing costs, including during Jerome H. Powell’s tenure as chair, and the Justice Department later opened a criminal investigation into Powell after he did not comply. The decision is also a test for Warsh, who had strongly criticized the Federal Reserve’s inflation response before taking the helm and pledged to eliminate inflation.