Biden and Dem leadership were saying it up to a few months ago, so it shouldn’t be hard to admit.
It was longer than a few months ago and they clearly said why they stopped even considering packing the Supreme Court.
Not only did they not have a congress to pass it, because they’ve never held anywhere close to enough of a super majority to get past fillibuster. But it’s also effectively handing a loaded gun to a second Trump presidency or any Republican presidency to do the same.
Candidates have to get a certain amount of signatures before getting ballot access on the primary in a state.
Williamson and Phillips weren’t able to do that everywhere, and Biden was, that’s on them not having as many campaign resources as a literal incumbent U.S. President, not the DNC somehow keeping them off the ballot.