> electeds? primary threat?

I'm familiar with American and Swiss elections. In both, the principal threat to an incumbent is from an own-party challenger to their seat.

For an incumbent, particularly one in a comfortable seat, an opposition candidate is usually not an issue. But someone from inside the camp is annoying and requires rhetorical contorting and lots of spending, spending that can then leave one vulnerable to an otherwise-benign opposition candidate. (Also, motivated activists are annoying in the best way.)

A smart elected–in these systems–will thus take a call to defuse anger before it develops into organized activism.

Ah, to clarify, Canada's upper house is basically a house of lords equivalent that we expect to be full of puffed up nobodies that get paid a too generous stipend to sit there and keep their mouths shut. Canada has one elected congress body (the one we all talk about) and then this vestigial senate which is generally expected to sit there and silently approve everything that passes through it.

It does technically have power, but it's like the King's power to veto UK legislation - he can do it precisely once and then he'll be stripped of the power.