Sentence:  There his vote , along with those of Chairman Howard Smith , the courtly Virginia judge , and the four Republican members , could and often did produce a 6 - 6 deadlock that blocked far-out , Democratic-sponsored welfare legislation ( a tactic often acceptable to the Rayburn-Johnson congressional leadership to <WSD>avoid</WSD> embarrassing votes ) . 
Meaning of the word marked with <WSD> tags:  prevent the occurrence of; prevent from happening