But iuf we are out by 2019 - ie have exited, who or what will the Brexiteers be aiming for then? Will they then be Back'ers and Remain'ers - where today's B's have become R's?
There are several unknowns - in particular:
Could there be an election before the Brexit deal is finalised?
Even if it is, there will be numerous 'loose ends' that will take decades to finalise.
Both good reasons to vote for an MP that represents your point of view on the subject.
P.S. for example, I would certainly wish for strong voices to oppose this:
http://www.bbc.co.uk/news/uk-politics-38037119