Such labels can serve to heighten political polarization, encouraging voters to see political opponents not just as mistaken but illegitimate, writes Stewart Prest.

White supremacists tried to move their practices further into the mainstream. Instead, it elicited a broad coalition in opposition.

If a Liberal stood for Speaker, the party would gain a measure of leverage over the government with the ever-present threat of withdrawal. Solve the NDP's problem in the present, and gain the ability to create a new headache for them down the road.