Because the EU has resisted the ultra-rich and the corporations in many ways recently (imposing rules, fining bad behavior) and the ultra rich just want to bully the world according to their whims which leads directly to the new attitudes in their party? Or could be the fact that russia also desperately wants the EU to be dead.

The republican party only serves the mega-rich and russian interests, so most of their actions can be explained by who gains from them, either mega-rich or russia.