They can do what they want. In fact, if Father Jenkins wanted to he could have all these charges dismissed immediately.
You are not making any sense now.
NDU is free under the Constitution to decide
that pro-aborts are NOT trespassing on NDU’s private property,
and that pro-lifers ARE trespassing on NDU’s private property.
What is it that you don’t understand?
You are correct to note that NDU was stupid to do so,
but that does not make it illegal or unconstitutional.
In fact, your views are very dangerous because you are advocating that private property owners cannot control who has access to its private property.
They can do what they want - they even have the right as private property owners to act like atheist secularists.
Being stupid and immoral (in this instance and under mosts circumstances) is not illegal or unconstitutional.