Having a serious dilemma here.
My dad is a hard core, conservative, maga, racist, homophobic, corporate, old-school oil company man. He was also an absent father, and at one point all three of my aunts, and my grandparents, cornered him to tell him he'd been a bad father all of my life.
We've tried to maintain some sort of relationship, but with all the fascishittery going on lately, I have no motivation to or desire to even acknowledge his existence.
Here's the kicker:
1/2
He's got Alzheimer's and is currently going down hill really fast. I'm being told that if I still want to talk to him, now is the time.
He's made several attempts to call over the last few months, and I've ignored them.
I have nothing to say to him that hasn't already been said, but the compassionate part of me thinks I should at least call him and ask him how his day is going.
I have some time today... I just don't want to.
Goddammit.
2/2
I have experience of both Alzheimer's in close family and have been on the receiving end of abusive terrible parenting. All I can say is you should do what feels best for you. You don't owe him anything and he won't remember you didn't call if you don't. On the other hand you need to be prepared for changes in his personality and the fact the him you know is going. You can't take it back once he's gone.
Fwiw there are no circumstances under which I would contact my dad.
DeadTOm 
Graceless Hippo