Should past presidents attend the inauguration?

Bottom line is Yes. All living Past Presidents should attend if they are able to attend unless they can't because of personal reasons. I also think that as a former Commander In Chief and former President of a Free Nation of the World it would only make sense and show solidarity among all parties concerned.

If it was protocol that previous presidents attend then yes they should. If not then they can do whatever they want. It's that simple.

I think someone said they needed to rearrange their sock drawer...

If they can, they should.

Should? Yes, a requirement? No.

They should from a moral standpoint.... But they are also free to do as they please.

"If you cannot respect the man, at least respect the office."

Donald Trumps photograph will be in every office you enter for at least the next four years.

Get used to it because in one month you will be required to follow any lawful order which he gives you.
If you are an active duty member of the armed services and do not do so you have disobeyed a superior.
I have little possibly no patience for any other talk.
However, as US citizens, and fellow human beings I will of course defend your right to pass air over your vocal cords.

Yes, they should attend. Even if you do not care for the man, it is a sign of respect for the highest elected office in our country.

YES TO ALL OF THE PRESIDENTS THAT LOVE AMERICA. FAKE, OBOMA, SOULD BE LEFT OUT.
HIS UNDERMINDING OF OUR CONSTITUTION REALLY PUTS HIM INTO THE TRAITOR LABLE .

there's a lot of history from the former presidents and the case of President Bush Senior he was shot down in combat and Rescue by a submarine. Even if GW bush was a drunk first lieutenant he still was a patriot flying a fighter plane for the Texas Air National Guard. most presidents before President Clinton served in the military. I believe it would be insulting to ask why shouldn't they be there?