For sure.
Liberals always excuse themselves from personally contributing their fair share. They reveal their own arrogance, as well, in that they feel their presence alone is enough of a generousity. 'Yes, you cannot take it to the bank; but I am a great memory'. . .
Personally, I would rather die poor, than be leave a cheap tip; and I think being generous with that tip is the fairest option for service.
. . .with no exceptions for 'who' you are.