"...Most liberals I know are of the Good-Hearted Liberal group..." That's probably true of most conservatives. We know other Leftists besides the good-hearted ones, but don't interact with them!
"...First, I asked him if he defines charity not as giving from the goodness of your heart, but having money taken from you by the government in the name of "charity." His back went up a bit...." Yes! That is a key distinction and it was quite astute of you to go right for it...there is a large chasm between "charity" and having money taken from you at the point of a gun to finance things that are anathema to you.
"...I explained that there was a sweet spot in the "rates of taxation" such that lowering tax rates of citizens and companies had the affect of increasing the amount of taxes taken in...." Hahaha! Good for you, discussing the Laffer Curve with a Lefty...that is another core thing they cannot seem to comprehend...taxing something too much reduces the amount of tax revenue you can raise from it. That is beyond their ken!
I will say, my brother's family is EXTEMELY leftist...and they raised one of their sons as such. If I didn't know for certain because they don't discuss politics with me (a wise move) it was confirmed when they accidentally included me on an email group they sent out after Trump won the election discussing ways to "Resist"...which by reading, means sabotage, not putting up ideas of your own that would work. We are still on good terms, but I admit I don't feel like visiting often.
BTW, check out the Democratic Socialists of America website. Lot's of good information in there.