This isn't that shocking to me. There were a lot of political and voter mercenaries last primary. Let's not forget that back in the 2016 primaries, both Warren and Biden polled ahead of Bernie in early parts of 2015, before it became clear that they wouldn't run. A lot of the Bernie vote in that primary, was folks who can't stand Clinton and just went with him as the anti vote. Now that their main choices are available, they are now going with who they wanted to back all along. The result is that Bernie has a high floor in 2020 having kept half of his support, but will lose guys like this dude to Biden who only supported previously to attack the Clinton's.