Joe Biden and his presidential campaign would be downright piteous if Biden himself were not so loathsome or if his presidency had been halfway competent. As it is, however, the attempt to pass off the 81-year-old president as the most effective Democrat for the job has descended into absolute farce. But even with a long list of disasters behind them, the Biden campaign’s news conference Tuesday morning outside the Manhattan Criminal Courthouse where his rival, former President Donald Trump, is on trial might have been the worst disaster yet. As the good folks on the social media platform X we…