Complex sentence: Chief Justice Fred M. Vinson, together with Associate Justices Hugo Black and Harold H. Burton, delivered a dissenting opinion in which they concluded that Kawakita, for over two years, was consistently demonstrating his allegiance to Japan, not the United States.
Split into simpler sentences: Chief Justice Fred M. Vinson authored a dissenting opinion, which was joined by Associate Justices Hugo Black and Harold H. Burton. The dissent concluded that for over two years, (Kawakita) was consistently demonstrating his allegiance to Japan, not the United States.