Sanders looks set to win Democrat leadership race, but he is no Obama

As Bernie Sanders handily wins the Nevada caucus, after finishing neck-and-neck with Pete Buttigieg in Iowa and New Hampshire, it is looking more and more like he is probably upstoppable in his push to become the the official Democratic candidate for the 2020 election.
Sure, the other Democratic leadership candidates are still talking themselves up -  after pumping all that money and effort into their campaigns, what else can they do? Joe Biden vowed (again) to bounce back; Elizabeth Warren said that, despite having lost again, she somehow has the momentum; no-show Michael Bloomberg just faded into the background; Pete Buttigieg contented himself with dissing the winner; and poor Amy Klobuchar seemed quite content with her 6th place finish, which seems like a good indication that she should save her money and bow out of the race.
Sanders confounded his opponents by finding support on all sides in Nevada, including among moderates, voters of colour, the middle-aged, and the non-unionized, and not just among his natural support base of the young, radical and white.
So, is this a good thing? However much I might agree with most of Sanders' policies and rhetoric, and however much I might respect his commitment and his energy, I can't help but worry that he is not the right person for the job. The "job", remember, is to beat Donald Trump. Nothing else matters even remotely as much. America needs to be saved from itself, and I could put up with pretty much any of the current Democratic leadership contenders (well, maybe not Bloomberg) if I thought they had a chance in hell of beating Trump.
To do that they need to take back some of the votes that swung to Trump for no good reason last time. But the more ideologically extreme Bernie Sanders is, if anything, more likely to push swing voters right into the hands of Donald Trump. For one thing, he is campaigning on a high spending platform, and is apparently not able to say how much it will cost or how it will be financed - how is that going to play with fiscally conservative America?
As things stand, and however bizarre the idea may be, I don't see any of the Democrat contenders having the strength and the moral authority to overcome the irrational and inexplicable appeal of Donald Trump, even after three or four years of what has undoubtedly been the worst US leadership in living memory. Buttigieg might have served - he is at least young, personable and refreshingly gay - but his policies are weak and his experience still weaker. Sanders, though, is just another old white guy (and, God knows, America has not been well-served by old white guys in recent decades). And his fire-brand policies and demeanour is not likely to endear him to swing voters and fence-sitters.
Oh, for a young, charismatic, moderate Democratic leader to sweep the country off its feet, and instill a measure of pride, ascendency and international respect again. Someone very much like Barack Obama... But alas there is no such candidate today.