I give him a pass for that statement. Biden was running on the platform of election trust and legitimacy. How else does he answer the question? “No, and I’ll fight tooth and nail to dispute the results if Trump wins?”. Maybe the democratic base would have loved to hear that, but it’s mixed messaging that would have been used as ammunition against him. He’s the President of the United States. He has to project confidence in the system, which means trying hard to win, but stopping right on the dot at “doing your best” and accepting the will of the people, even if it’s a distasteful outcome for everyone involved.