I think it is far to early to discuss Democratic debates. First, Biden is an incumbent president and primary challenges when running for a second term always damage them in the general election. Reagan v Ford, Kennedy v Carter.

Second, yeah there are two other declared challengers who are currently polling single digits.

I am a progressive Bernie/Warren voter and I do not see Williamson as a viable candidate and she would be as far out of her league as president as Trump was. Enough with the celebrity-president shtick.

Kennedy lost it with his anti-vax rhetoric.

Debating them would falsely elevate them both as viable candidates. They aren't. At least not now.