Switching power to a device from a microcontroller
Using a high side p-channel mofset transistor is not preferred because it would require a constant voltage to keep the lcd screen off.


This statement doesn't make sense. A P channel MOSFET and pull-up resistor is a very standard way of switching a power rail. Switching 5V from a 3.3V GPIO pin takes a couple extra components.







simulate this circuit &ndash; Schematic created using CircuitLab

A logic high on the GPIO pin will turn your switched rail on. C1 is optional. It is there to limit the inrush current by slowing down the \$V_{GS}\$ transition. You'll probably want it there if there is significant capacitance on the switched net. That verification is up to you.