This was a good choice.  It was a bad promise and I would rather leaders back bad promises than keep them and feel the results.  It was much like Chretien's promise to scrap the GST which was a dumb one and broken and he still got re-elected three times.  Asides from a few types at fairvote who have this as their top priority, I doubt it will make that much difference in 2019.  If Trudeau is defeated or reduced to a minority it will be because of other issues not this one.