Bernie has been "tone policed" beyond anything I've ever seen. The irony is that to a large part of

[irisblue]

137. From Slate.com OCT. 5 2015 3:05 PM by Mark Joseph Stern

Bernie Sanders Claims He’s a Longtime Champion of Marriage Equality. It’s Just Not True. (Whole article online) some excerpts
..."As proof of his pro-LGBT credentials, Sanders frequently touts his opposition in 1996 to the Defense of Marriage Act, which barred the federal government from recognizing same-sex marriages. But Sanders is not quite the gay rights visionary his defenders would like us to believe. Sanders did oppose DOMA—but purely on states’ rights grounds. And as recently as 2006, Sanders opposed marriage equality for his adopted home state of Vermont. The senator may have evolved earlier than his primary opponents. But the fact remains that, in the critical early days of the modern marriage equality movement, San
ders was neutral at best and hostile at worst....But Sanders’ efforts to parlay this vote into indisputable proof of his marriage equality bona fides ring hollow in light of his statements at the time. Explaining his vote in 1996, Sanders’ chief of staff told the Rutland Herald that Sanders’ vote was motivated by a concern for states’ rights, not equality. Explaining that he wasn’t “legislating values,” she noted that Sanders believed DOMA violated the Constitution’s Full Faith and Credit Clause by allowing one state to refuse to recognize a same-sex marriage performed in another. “You’re opening up Pandora’s box here,” she said told the Burlington Free Press at the time. “You’re saying that any state can refuse to … recognize the laws of another state if they don’t like them.”...
Ten years later, Sanders took a similarly cautious approach to same-sex marriage. In 2006, he took a stand against same-sex marriage in Vermont, stating that he instead endorsed civil unions. Sanders told the Associated Press that he was “comfortable” with civil unions, not full marriage equality. (To justify his stance, Sanders complained that a battle for same-sex marriage would be too “divisive.”) "

I cannot c&p the whole article (TOS& copyright).
It is less then a 10 min read.

Sanders has evolved, but I disagree with redgreenandblue assertion that he was there on LGBTQ equality & rights " far before the Democratic mainstream." The mayor of Columbus Ohio, Mike Coleman, was already supporting LQBTQ equality then, I lnow this because I was volunteer working on Pride Parades then.
I do agree with dsc, trying to rewrite history isn't going to work. It's easy to check written & archieved statements now.

As an Independent, aligned with the Democratic Party, he's truly an interesting philosophical mix.