This is going to be a huge negative for republicans. Almost worst case scenario
Maybe. But maybe not. I agree that the President will make the most of his nomination being stalled, and McConnel and gang will likely engage in their usual political ineptitude. On the other hand, the one possible silver lining of losing such a brilliant and principled jurist is that this could potentially unify the GOP no matter who the nominee is. Even if it's Trump or Cruz, if the question is whether Hillary will pick Antonin's replacement, the base will show up at the polls.
Again though, politics aside, this is a devastating loss for the Court and for the rule of law. Scalia was also a kind and decent man. I had the pleasure of meeting him once as a law student. I asked what was in all liklihood a very stupid question about a case he'd written the opinion on. He wasn't condescending at all. He was a class act. His opinions - particularly his dissents - are jurisprudential works of art. Even at 79 it just feels like he left us way too early.