The Proposed design used wings derived from the P-38 Lightning, on a radical blended wing-body concept with canards to increase maneuverability. Johnson promised speed of up to 620mph (mach .9), but the USAAF wasn’t willing to take the risk on such an advanced aircraft - especially since the powerplant was undeveloped as well.
Ultimately, Lockheed produced a much less avant-garde fighter in the P-80 Shooting Star, which led the way to the jet age in the U.S.
But all that leaves us wondering what would have happened if the Starjet took to the skies…