Prominent members of the party said Sunday that Democrats having nothing to worry about if President Biden remains their nominee, though a few acknowledged concern—which could be increased by the devastating findings of a new poll. Biden made no public appearances Sunday; he was spending the day at Camp David with his wife, children, and grandchildren in a gathering scheduled before his shaky debate performance against Donald Trump on Thursday night. The day was being partly devoted to taking family photos to be used at the Democratic National Convention in August, per the AP. Biden’s family u…