I'm sorry, but this defines "conservatism" by whatever canyon -- large or small -- existing in contrast to your "most conservative candidate" approach.
With this approach, you get your frog-in-the-kettle so-called "conservative" -- he just gets boiled a few degrees hotter every election -- until you wind up having 1960s Democrats who were on the average more "conservative" than your 2012 or 2016 "Republicans."
Because someone is a Democrat that doesn't mean he votes Democratic.
Also,....Maybe we could learn something from the communist Antonio Gramsci. He believed in gradually infiltrating society's institutions and corrupting them. Maybe...Conservatives could use the same tactics by invading Marxist organizations and corrupting their purpose to our good?