Wiktionary
wedge politics
n. (context politics English) A strategy or pattern of behavior by a politician, political party, or advocacy group which is intended to have a divisive effect on one's political opponents or on the electorate, especially by emphasizing an issue which polarizes opinion along racial, regional, or other demographic lines.
Usage examples of "wedge politics".
The country had been going in one direction for more than a decade, living with wedge politics, reassuring bromides about how great we were, and the illusory, though fleeting, comforts of spending more and taxing less today and ignoring the consequences for tomorrow.