the race card
The act or tactic of introducing the issue of racial discrimination, especially against the race one identifies as, in order to gain an advantage in or dismiss or discredit an argument. Typically used in the phrase "play the race card." There you go playing the race card again. I don't care if you're purple—I still think it's a bad policy! I hate it when casual racists try to brush off legitimate criticism by claiming that you're just "playing the race card."
*race card
Cliché the issue of race magnified and injected into a situation which might otherwise be non-racial. (Typically: deal ~; play ~; use ~.) At the last minute, the opposition candidate played the race card and lost the election for himself.