You can tell he hears bits and pieces of the Democratic platform (in this case working to reduce agricultural greenhouse gas emissions) and just twists it up in his head in ridiculous and nonsensical ways. 

The idea that Democrats want to ban windows in buildings from the same rant is a little harder to parse, but I think it's from the idea that Democrats suggest replacing windows in old buildings with more energy efficient windows.

It would be hilarious if he wasn't running for president.