I'm absolutely positive about that.  Stephen Harper had the opportunity to come to power and lasted for 10 years solely because the LPC was consumed with internecine warfare.  As soon as that resolved with the election of someone who had the backing of virtually the entire party, Stephen Harper was gone.

Those circumstances will not pertain in 2019.  PM Trudeau may well alienate enough supporters to lose in 2019: Bernier can't win otherwise.