In some states you have to declare your party before voting, but I don’t know if that’s a hassle or not. I would vote for Bernie simply because he would get shellacked so badly even the liberals couldn’t quibble about the outcome. I think it would eclipse George McGovern’s loss.
In VA you pick the primary ballot you want. They hand it to you. No questions asked.
To make things worse for the Democrats, if polled on your way out of a primary voting for Bernie, tell them you are a hardcore Communist and support Bernie’s call for overthrowing the US government by force and violence.
The look on the pollster’s face would be “PRICELESS”!