Wedge Issue

A wedge issue is a divisive or highly controversial issue that divides or “drives a wedge” between groups of people or factions that cause weakness and disunity within a larger group.

Example:

The party emphasized the opposing candidates’ positions on wedge issues in an attempt to divide the voters and create chaos and infighting in order to win the election. It was a brilliant strategic move because the opposing party and candidates spent all of their time discussing wedge issues that created even larger rifts and trying to reunify the party that they did very little standard campaigning.