I don't know if these are real receipts but the do pretty much sum up the campaigns and supporters of both these two candidates.
Both candidates are appealing to the mirror image of the same people. Middle class white people who are feeling disenfranchised and the idealistic, somewhat naive and a little spoiled young people. Both candidates represent the extreme of their party's ideology.
I know that Sanders believes in what he is saying even if he can't describe the details of how he is going to get to where he wants to go.
I am certain that Trump only believes in Trump and has not a clue as to what he is talking about.
An actual tip would have been about $9 maybe if this person was really sincere they would have left a 20% tip and then add the $15 on top of it.
This person is either a disgusting asshat or the service was terrible and they just wrote this in a moment of snark.