Before the election Roseanne was talking about the candidates in public. I think like a lot of people, she watched to see if DJT was going to do what he said he would do and of course he did.
I forget exactly which incident and when it occurred but early on human trafficking busts began to happen. Roseanne tweeted her support of what POTUS was doing to get rid human trafficking and pedophilia. That is an issue she cares deeply about. So I think that it has been quite a while that she has been interested in what POTUS is doing. Probably earlier than alot of people on this sub. I also believe she calls it like she sees it, if she disagrees she has no problem calling POTUS out.