Based on Chapters 5-9 of Ian Haney López's Dog Whistle Politics: How Coded Racial Appeals Have Reinvented Racism and Wrecked the Middle Class: What are the punch and parry techniques?

The "punch and parry" technique of dog whistle politics involves three distinct steps. First, in the punch, the practitioner of dog whistle politics injects or punches race into the political conversation by using references to "culture, behavior, and class" (page 130). Then, in the parry stage, the same person parries claims of racism by stating that there was no overt use of racial epithets or references to the biological basis of race. Finally, there is a kick phase in which the practitioner of dog whistle politics kicks up the racial debate by claiming that the person who has charged the practitioner with racism is the true racist. In other words, the person who has used racist appeals claims that his or her critics are the real racists because they have injected race into the conversation while it never before existed. 
The example the author uses of this technique is the cartoon of Obama that had a picture of him as a donkey alongside watermelon and fried chicken. The cartoon read "ten dollars Obama bucks" and "United States food stamps" (pages 127-128). The person who printed this cartoon used the punch and parry technique by punching race into the conversation by linking Obama, a Black President, to food stamps and to stereotypically Black food. Then, the person parried the claims of racism by claiming that it was not at all racist because there was no overt reference to race. Finally, the person kicked the charge of racism back to the critics of the cartoon.