I just had the same problem the other day with a Dem who was rehashing once again Bush’s war in Iraq. I asked him if he ever read the Authorization for Use of Force in Iraq, pointing out that it was a Democrat-controlled Senate that passed it. For some reason, that little fact had been deleted from his memory banks and replaced by a self-invented ‘fact’ (e.g. “Bush rushed to war”, “the Republicans did it”, etc.) that better satisfied his emotional needs.
My ultralib brother-in-law was getting huffy about how the evil Bush had forced us into war when I simply said, “Hillary Clinton voted to go to war with Iraq when she was a senator.”
He immediately shut up.