BullNBear52, Sanders did claim to be a Democrat more than once.
Signing a political affiliation form as a Democrat, so as to be able to run as a Democrat, was a claim to be Democrat for a time.
The fact that voters in NY had to register as Democrat to vote for Sanders is good evidence that Sanders was a member of the Democrat Party during his campaign.
Sanders in referring to the DNC at least once called it 'our DNC'.
"How do you respond to what Martin O'Malley said on Friday night?
SEN. BERNIE SANDERS (I-VT), DEMOCRATIC PRESIDENTIAL CANDIDATE: Well, let me -- let -- let me respond. I am proud of the fact that that I am a longest serving Independent in the history of the United States Congress. That's what the people of Vermont voted for. I made a decision in this presidential election that I will run as a Democrat. I am a Democrat now." .. just under half-way down, under the Trump-Carson stuff .. http://abcnews.go.com/Politics/week-transcript-donald-trump-ben-carson/story?id=35044135
No need to apologize for disruption .. you gave an opinion .. it was my needle ..