It's not new, he's been saying this since 2015, well before the referendum.
What's alarming is he's saying it at a Lib Dem Conference, and being loudly cheered for it.
The election of Jean-Claude Junker as commission president was said to a 'crucial step' towards United States of Europe in 2014.
theparliamentmagazine.eu/articles/opini…
"My goal is the United States of Europe - on the model of the federal states Switzerland, Germany or USA,"
spiegel.de/politik/deutsc…