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a very divisive political issue used for drawing voters away from an opposing party whose supporters have conflicting opinions on it
Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree
A sharply divisive political issue, especially one that is raised by a candidate or party in hopes of attracting or disaffecting a portion of an opponent's customary supporters.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
an issue that is likely to cause division between the members of a group
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
an issue that divides or causes conflict in an otherwise unified group: Abortion is a wedge issue for the Republican party.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.