Complex sentence: At one point, Murray had the opportunity to form a ministry with himself as premier; but the move failed when he was unable to enlist the support of those fellow Members of Parliament who considered him to be intellectually arrogant.
Split into simpler sentences: At one point, Murray had the opportunity to form a ministry with himself as premier. But the move failed when Murray was unable to enlist the support of sufficient Members of Parliament, a number of whom considered him to be intellectually arrogant.