People of all political stripes sometimes say things they don’t mean, or come to regret, in the heat of passionate argument, either out of anger or just for dramatic effect.
The Sun newspaper once famously warned the last person fleeing Britain in the event of a Labour election victory to “turn out the lights”. Every Labour Party campaign in living memory has warned voters that they had only “24 hours to save the NHS”, though somehow it never seems to disappear in the Tory years. Paddy Ashdown said he would eat his hat if the Liberal Democrats did as badly in the 2015 general election as the exit poll predicted (they did worse).
Meanwhile, across the Atlantic, angry liberals threatened to move to Canada when George W. Bush was re-elected, while social conservatives – high on passion but lacking in international awareness – responded to the Supreme Court’s ruling legalising gay marriage by themselves threatening to move to Canada, that well-known bastion of homophobia and social conservatism.
So rhetorical hyperbole is not restricted to any one political party or any one type of outlook or worldview. But there is a certain type of political argument to which those on the political Left seem to resort far more often than their opponents on the Right.
When faced with electoral defeat and years in political opposition, those of a conservative mindset tend to lick their wounds for awhile and then set about the business of trying to re-acquire power and influence, however angrily or unsuccessfully. However, when those of a left-wing mindset are faced with rule by the other side, they are far more likely to view the situation as intolerable to the extent that even remaining part of the same country or political structure becomes undesirable.