evidence: US President Joe Biden has admitted he "screwed up" in last week's debate against Donald Trump, but has vowed to fight on in the election race and moved to reassure key allies. [...] A fundraising email sent after the call by the Biden-Harris campaign was also bullish. "Let me say this as clearly and simply as I can: I'm running," Mr Biden said. [...] Members of the Democratic National Committee are charged with voting to officially make President Biden the party’s nominee at the August convention, putting him on the ballot nationwide.