In order to get a veto chance in the regular session.
A special session is very hard to do and I don't think dems will pull that off. However, I HAVE been hearing talk from some of them that they are planning to call one to override vetoes. I guess they realize they've been moving too slow and Hogan is likely to veto a bunch of their stuff they care really deeply about and they don't want to have to spend a bunch of legislative time next session once it is a new legislature having to re-introduce, hold hearings, debate, etc.
From their perspective I can get it. I don't like it, but I can get it.
I hope they don't get what they want.
They have to have an issue to call a special session about. They can't call one just to over ride vetos.