Keep in mind that it was the long-haired, dope-smoking, free-love hippies that evolved into the Yuppies that voted Reagan into the Presidency. Twice. By landslides.
In politics you find allies and common ground wherever you can, trusting that your new allies will “grow” in your direction politically and ideologically. Or at least grow away from the other side.
It’s not just Cruz who gets this; Trump does too. BOTH are working towards a deep and robust winning coalition.
“Long-haired, dope-smoking, free-love hippies” were actually a very small part of the voter group that you reference.
Most of those voters were not, at any time, radicals... they just wanted to go to class, graduate and get a job. They wanted what most Americans (regardless of generation) want: an opportunity for security, liberty, prosperity and peace.
They grew older and logically voted for Reagan. Hipster millennial Paulite libertarians (and their old and crusty compatriots) are not similar to the Reagan baby boomer voters.
They are fringe heavy-baggage types who may account for a marginal at-the-polls advantage and a multitude of future political headaches.