Complex sentence: It may be noted that these were fairly low-ranking positions for an ex-leader; it is possible that Spivak did not want to serve at a higher level in a ministry from which he was ideologically disengaged.
Split into simpler sentences: It may be noted that these were fairly low-ranking positions for an ex-leader. It is possible that Spivak did not want to serve at a higher level in a ministry from which he was ideologically disengaged.