Complex sentence: He has been accused by his opponents that he was not the choice of Croats, but rather Bosniaks, citing that he did not win majority for Croatian representative in any of the counties/cantons with Croat majority.
Split into simpler sentences: He has been accused by his opponents that he was not the choice of Croats, but rather Bosniaks. He did not win majority for Croatian representative in any of the counties/cantons with Croat majority.