Giving this tenant money every month (in the way of reduced rent) is far less impactful than giving $100 worth of groceries per month to a soup kitchen, or donating $100 month to a worthwhile cause.

Also, make it illegal for previous government employees to work in lobbying firms.Make it illegal for anybody with a net worth of over a million to donate more than $5000 in campaign contributions.

What can i do if a city where i own a property, announced they need a part of my land for a community project, and i can either 'donate' the land or get a 'just compensation' ?

Be a good landlord and follow the law, if you still feel guilt after that donate your money to charity.

If they're paying $1,000 a month just to cover the mortgage and it would ordinarily rent for $1800, that's almost $10,000 a year you are "donating" to them in the form of lower rent.

The family has offered to donate it to them, but the university has put that off (long story--bureaucracy is short version).  

He can donate the properties to charity if he is that against paying tax on them.

@John Bosse well the seller took the washer & dryer with them, the fridge we just donated to the Salvation Army, but the oven we got $50 for on Craigslist!

It's a big change in numbers there for me.It has to be passed. but California Senate President Pro Tempore Kevin de León, a Democrat, and two other senators, have introduced a bill in that state's legislature that would allow individual taxpayers to make a charitable donation to a new state fund and receive a credit for the full amount paid to that fund on their California income tax return. 

He did mention he wanted his money to go to charity, so I was pitching to him that he'd be alive and able to donate the house proceeds to charity himself and see the good that it does while he's still alive; so we shall see.