Preach is a synonym of Advocate. Democrat is a type of Advocate. 
Operating is related to Drive. Car would make you want to Drive. Car is related to Gas. Gas is related to Commodity. 
Preach <--Synonym--> Advocate <--IsA-- Democrat 
Operating <--RelatedTo--> Drive <--CausesDesire-- Car <--RelatedTo--> Gas <--RelatedTo--> Commodity 