Complex sentence: Before being elected he worked for the Republican Party on the 1994 senate campaign of Jim Inhofe in Oklahoma as a professional heckler, which earned him the label of "a foreign political saboteur" from CNN.
Split into simpler sentences: Before being elected he had worked in the United States for the Republican Party for the 1994 senate campaign of Jim Inhofe in Oklahoma as a professional heckler. This earned him the label of "a foreign political saboteur" from CNN.