Complex sentence: Malghan felt that post-modernism had failed in its avowed intention to challenge traditional power structures and had combined with politcal correctness to become a stifling orthodoxy in its own right, tending to dominate the fine art photography scene in America to the extent of stifling everything else.
Split into simpler sentences: Malghan felt that post-modernism had failed in its avowed intention to challenge traditional power structures and had become entangled with politcal correctness to become a stifling orthodoxy in its own right. It seemed to Malghan that post-modernism had come to dominate the fine art photography scene in America to the extent of stifling everything else.