Just look at the polls. You may not believe them, but Trump is neck to neck or even leading in some of them. The scary part is that traditionally Trump has done better than the polls suggested. The problem for the Dems is that most of the younger potential candidates are toward the liberal end of the Dem spectrum and may not appeal to independents and more traditional voters. The world is in pretty much of a mess right now. Prices are rising more slowly, but still high in food, housing, transportation and medical care. The war in Ukraine has ground to a stalemate, and now Israel/Hamas are going at it. The border is a disaster and crime is still high. These situations may not be Biden's fault, but it is easy to blame them on the incumbent, and Biden's appearance of feebleness and horrible public speaking abilities dont help to refute them.