Sentence:  In 1702 he wrote  in opposition to prevalent intolerance a phamphlet entitled "The shortest way with Dissenters," in which he counselled the violent and total extinction of all who differed with the state-sanctioned creed. He was, of course, out-Heroding Herod to mock <WSD>Herodism</WSD> : but his imitation was too good and he was clapped into Newgate and condemned to the pillory. 
Meaning of the word marked with <WSD> tags:  The killing of unwanted people, especially children.