"What if this becomes a pattern applied to other taxes that low information voters don't pick up on? Trudeau has to go in 2019."

What happens is this:

-The Liberals get their eventual boot either next election or the one after. 
-They, in Opposition, moan and decry the Cons for all the unfair taxes with no accountability.
-"Independent" "3rd parties" "advocacy groups" spend a bunch of marketing dollars railing against the Cons for "their" unfair taxation.
-low information voters, buoyed by public sector unionistas, buy the nonsense and we get another "Anyone But {Harper}" election with a high possibility of electing a doofus in protest.