Neither is Trump a Conservative. Just as the alignment of the Allies in WW2 was built around the common enemy, so too is the relationship between Trump and 'conservative' voters. The common enemy is the Republican Establishment. Or so the voters seem to think it is. What evidence says that Trump also has them as an enemy?
When the war ended, Stalin's Russia went from ally to enemy seemingly overnight. Recall that the US airdropped food to Berlin for over a year starting in 1948. Similarly, would Republican voters, dying to be taken seriously by its party leadership, be facing a new enemy seemingly overnight in their former ally Donald Trump?
Other than brash talk about bullying the world into our will, I've heard nothing from Trump that explains the reasons he no longer holds all his previously liberal positions on socialized medicine, abortion, and such. Why is he waiting until now to make immigration an issue? Trump could have been purchasing Super Bowl commercials for the last decade to persuade people on his immigration position. Yet he didn't. Why not? Why is this issue only NOW important?
It's reasonable to conclude that immigration is merely a stepping stone for Trump to use to fool Republican voters. Angry at the establishment that continues to ignore them and undermine them, these primary voters are all too easily led off by the Pied Piper of Primaries.