When I heard Obama, yes, inspirational; but I have a worry.
Obama has (done as Trumps has for four years) broken with long-standing tradition and precedent, and publicly called out the current president, his successor, as a liar and a menace to the country. This is going to underline, for Trump's supporters, that Obama breaks the rules and is a Bad Man.
What worries me is that some undecided Republicans, who may well have been thinking they simply can't bring themselves to vote for Trump this time, may be pushed into thinking that the Democrats are just as bad, breaking the rules like this, and that they might vote for Trump after all because he is being attacked in this underhanded way.
I fear desperately that it may be a "basket of deplorables" moment. If the Trumpist media play it that way, it could be made very bad for Biden's chances. I hope they won't, but deeply fear they will.