re: Do liberals actually bring anything of value to this country?

They create a lot of great art and music (along with a lot of mediocre art and music).

They gentrify bad neighborhoods and make them safe and cool.

They build restaurants and bars.

They improve parks and beautify neighborhoods.

They teach children.

They create and run all kinds of worthwhile charities.

The problem is that there are so many bad ones that use virtuous causes for corrupt ends, and so many who are duped by those people into supporting that corruption. Most liberals are not bad people, they just allow their emotions to cloud their judgement into supporting policies which do more harm than good.