Quite the contrary. If Trump gets elected, Europe finally needs to realize they can’t rely on the US and take their own steps to ensuring their security. It should have happened after 2016 really, which makes me skeptical anything will convince them.
It’s as simple and difficult as finding common ground with many of the various groups on the left. I think there IS a cause that we can all agree on - wealth inequality because it’s the cause and/or symptom of most of the other problems we champion - and we need to unite behind that so we can be an electoral force. There are enough of us if we voted together.