Wedge issue
（重定向自Wedge politics）
A wedge issue is a political or social issue, often of a controversial or divisive nature, which splits apart a demographic or population group. Wedge issues can be advertised or publicly aired in an attempt to weaken the unity of a population, with the goal of enticing polarized individuals to give support to an opponent or to withdraw their support entirely out of disillusionment. The use of wedge issues gives rise to wedge politics. Wedge issues are also known as hot button or third rail issues.