Noun
wedge issue (plural wedge issues)
(politics, social relations) A discussion point or a difference in points of view which is particularly likely to be controversial and a source of discord between discussants or other involved parties; a difference in viewpoints which causes disharmony within a political or social group.
We cannot shun our values as an immigrant nation. This is a wrong path. And while possibly it is a short-term political victory based on division and based on creating a wedge issue that splits people in this country, it is a long-term defeat for this Nation. Raul Grijalva