1. The whole debate about "enthusiasm" for Biden is badly framed. In normal election, Democrats need both their loyal partisans and more marginal voters (who tend to be younger & poorer). Clinton 2016 had plenty of enthusiasm among partisans but fell short with marginal voters.
2. In the abstract, Biden looks to have many of the same problems as Clinton. He's super-popular among partisan Dems, but struggles with marginal (particularly young). In most states he lost primary vote of voters under 45.
3. So: if this were a normal election, I'd worry about Biden. But 2020 is hardly normal. Trump is super-unpopular among Dems, including marginal voters. And while he's enjoyed a crisis bump, it's likely to fade after months of coronavirus & recession.
4. Also: the real source of Biden's appeal, which might extend beyond partisan Dems, is that he's NOT exciting: he's running as a generic Dem, a return to normality, a Democratic Warren Harding. Given crisis situation, many voters fight that attractive.
