The Toronto Star has a significant-looking headline this morning: "Justin Trudeau, Liberal support, dip over pro-choice stance".
The first five words were mostly correct, the rest were a bit of a leap. This concerned a Forum Research poll showing the Liberals down three points since the end of April. But that is all the poll showed, as no questions relating to abortion were included with the survey and, thus, there is no evidence to link the (statistically insignificant) drop of support to his abortion stance. It could have been related, or the drop could have been because Trudeau looks a little bit like Brian Boyle of the New York Rangers (the Liberals did drop in Quebec, after all).
This wasn't entirely the fault of the Star, however, as the headline and the lede were merely echoing what the analysis included with the poll was saying.
Unless they are expressing their opinions as close observers of politics separate from the analysis of a poll, pollsters must limit themselves to what their own numbers show. Otherwise, they are giving their opinion the semblance of authority, of evidence-based observation, when that is not the case. There was nothing in the Forum poll that suggested the drop was related to Trudeau's abortion stance, unless you consider an increase of support for the Liberals among evangelical Christians to be sarcastic.
I wrote about this poll and this issue in more detail for The Huffington Post Canada today. Please go check it out.