I don't know who the Democrats have that could step in and make them feel confident. The GOP has DeSantis, and I think he would win pretty easily if Trump is willing to step aside and endorse him. Or, if he could get DeSantis to agree to be his running mate, I think they'd steamroll whoever they faced, with the hope of priming the VP for his own run in 2028.
I think Hillary Clinton will make some noise, but I don't think she can win now, in part because I think her own party would not want her back. Some might put forth Michelle Obama, but she did not seem very involved in politics and would really only be banking on Democrats' good feelings about her husband's two terms. Other than that, many of the names don't inspire confidence. The younger ones, like Buttigieg or O'Rourke, have had limited success and don't strike me as strong candidates. Sanders looks even older than he is. Warren has too much baggage, and that is just the stuff that we know about. AOC is too young, isn't she? And far too radical in a time when far-left policies are seen as the cause of much of the current socioeconomic turmoil.