Constitutionally protected free speech exists in Canada but it has limitations. The issue I think you're conflating is how you apply currently existing limitations on free speech, which exist for hatred, for defamation, for slander, for copyright, etc., to the online world. So that's the first point.
The second point is that if you're going to protect candidates, you need to protect all vulnerable candidates. Let's talk about the Islamophopia that Iqra Khalid faced. Let's talk about indigenous peoples in Saskatchewan in the wake of the death of Colten Boushie and the Gerald Stanley trial. You need to be thinking about this across the board, because there's a problem recruiting anyone who's Muslim, Jewish, indigenous, or black to get into this seat and into this chamber when we have such invective spreading online.