It’s been evident for months now that DNC chairwoman Debbie Wasserman Schultz is denser than lignum vitae. She should have sensed last fall that she was no longer welcome in her position, even from the Clinton camp which supposedly was advantaged by her partisan support. The administration wasn’t happy with her, the Clintons have been looking to dump her for months, and the Sanders campaign and their supporters have been gunning for her since the debate schedule was announced last summer. Apparently, the only thing that saved her was that no one in a position to have her sacked was motivated enough to deal with the hassle. Here’s a couple of different spins on that:

Clinton’s team has long known that Wasserman Schultz was an unpopular chair. But the feeling inside the Brooklyn campaign headquarters was always that her removal was not worth the time, effort or public brouhaha that would result.

John Podesta, Clinton’s campaign chairman — and a former top adviser to Barack Obama — broached the idea of replacing Wasserman Schultz as early as last fall, only to be rebuffed by the president’s team, according to two people with direct knowledge of the conversation.

“It came down to the fact that the president didn’t want the hassle of getting rid of Debbie,” said a former top Obama adviser. “It’s been a huge problem for the Clintons, but the president just didn’t want the headache of Debbie bad-mouthing him. … It was a huge pain in the ass.”

You don’t have to sort that out. People talked about her being a disaster and about options for replacing her. But, ultimately, it was just easier to try to ignore the problem.

It’s been painfully obvious for weeks and weeks and weeks that Wasserman Shultz has irritated Sanders and his supporters to the point that she was one of the biggest obstacles to the party coming together. We didn’t need to read a private memo from the Sanders Team to know that ousting DWS was on the list of their key post-California demands for making a Clinton endorsement. All the Wikileaks revelations have done is provide the heretofore missing motivation for moving her out.

Yet, apparently, Wasserman Schultz tried like grim death to hold on to her position all weekend long, only agreeing initially not to address the convention. It took a massive intervention to persuade her even of that, and she still expects to gavel in and out the Philadelphia festivities.

Then, this morning, she made the stunning error of trying to address her home state Florida delegation, only to get booed off the stage Ted Cruz-style.

The Florida lawmaker, who will resign after this week’s convention in response to the disclosure of emails that showed top members of the DNC working to boost Hillary Clinton’s primary bid, had to strain her voice to yell over the flurry of protestors who showed up to interrupt her speech.

“We need to make sure we move together in a unified way,” she said over shouts from the crowd.

As she spoke, people stood on chairs holding up signs that said “emails,” “No!,” and “Thanks for the ‘help,’ Debbie.”

Others repeatedly shouted: “Shame.”

The heckling didn’t stop even as Wasserman Schultz mentioned last night’s shooting in Fort Meyers, Florida, that left two dead and more than a dozen injured.

Wasserman Schutz was defiant, insisting delegates would see more of her.

“You will see me every day between now and Nov. 8 on the campaign trail and we will lock arms and we will not stand down,” she said.

She also took on those heckling her.

“We know the voices in this room that are standing up and being disruptive, that’s not the Florida we know. The Florida we know is united, the Florida we know will continue to create jobs,” she said.

Yet the remarkable scene raised more questions about the wisdom of having Wasserman Schultz gavel the convention in and out.

She must be the last person in America who thinks she isn’t persona non grata in the convention hall and that it would be in any way helpful or even appropriate for her to preside over any part of the proceedings.

She reminds me of Donald Rumsfeld, who talked about Dead-Enders in Iraq but wound up being the worst Dead-Ender of all in the Bush administration. While it’s true that there are known unknowns, things that we know we don’t know, and there are unknown unknowns, things that we don’t know that we don’t know, there are also known knowns, like the fact that Debbie Wasserman Schultz should get on the first flight out of Philadelphia International Airport.

And that she should not look back.

UPDATE: She’s so dense that the decision had to be made for her, and now Rep. Marcia Fudge will handle the responsibilities of chairing the convention for the DNC.