That is because Trump has completely turned the tables on the Dems. The Dems are the ones who won't cut a deal to protect the Dreamers. Trump smoked them out as extremists who simply want a campaign issue. Much more satisfying than the hapless establishment GOP, which simply wrings its hands when the Dems attack and tell the base that there is nothing that they can do other than cave in.
Trump and some Republicans started to make the claim that the Democrats cared more about illegal aliens than legal Americans. The Dems are terrified of that issue—an issue that will resonate in the Congressional elections in swing districts.