That’s the thing, though, no one “puts forth” a candidate except the candidate themselves, parties will sometimes reach out to activists or local party officials for local or state office nominations, but Federal office candidates are almost always decided by candidates themselves getting signatures and putting their name forward.
You’re no more responsible for the failures of the party than party establishment officials at the DNC, and likely quite less responsible, but you are responsible for writing off the party as a whole, and thereby abandoning the about 50% of the party that wants to take it in a progressive/anti-capitalist direction.