Bernie is not for open borders. Here's an interview where he says it.
He's actually more of a nationalist/socialist. He's for the workers of America. I guess you could say he's sort of for a nationalist socialist workers party. Wait...where have I heard that before...
Some of the dems are flat out for open borders- and some even go beyond that. Castro went to Mexico and helped escort some migrants up. Booty wants bring back anyone who was deported or previously denied entry and even pay them reparations for it.
And then you have this clown-class of devious democrats who say they are not for open borders but then they list off all the things they would do that obviously lead to open borders: abolish ice, decriminalize illegal entries, amnesty for all, sanctuary cities, fee citizenship, free medical care and all the incentives to come. But they will tell you that they are only for legal entries- except they can't think of anything that would be illegal.