New Delhi, March 12 -- President Donald Trump's nomination of Kevin Warsh to lead the Federal Reserve has landed in the Senate. What happens next is less clear.

Warsh, a former Fed governor, is expected to face a tough confirmation process even with Republicans controlling the chamber. The immediate obstacle isn't opposition to Warsh himself. Instead it is an investigation into current Fed Chair Jerome Powell that has created a procedural standoff inside the Senate Banking Committee.

Sen. Thom Tillis of North Carolina, a Republican on the panel, has said he wouldn't support moving any Fed nominations forward until the Justice Department resolves its probe into Powell. The investigation centers on Powell's testimony to Congress last year...