Why indeed? A good answer to this question does exist, but let's start with the fact that Jon Karl made this a good question first.

Both Duane and I wrote about the segment yesterday on This Week in which Jon Karl appears to have conjured up a policy change that Kamala Harris has never personally articulated. Sen, Tom Cotton argued that Harris would enact radical policies like eliminating private health insurance, a position that Harris took publicly in the Senate by co-sponsoring Bernie Sanders' Medicare for All bill and then proposing one of her own in 2019 during her presidential run. Despite the fact that Harris has never personally repudiated that position, Karl tried to fact-check Cotton during the segment by claiming that was no longer her position, apparently based on an anonymous campaign leak to Politico.

Needless to say, this brings back some debate memories from 2012, when Candy Crowley attempted to fact-check Mitt Romney on Barack Obama's Benghazi response and got it entirely wrong. If ABC's attempting this kind of pro-Democrat spin during its news interviews, one has to wonder how they'll handle a presidential debate, especially one involving Donald Trump.

Trump himself openly wondered about it overnight, in fact, including whether he should bother going forward with it at all. Trump had a couple of other examples of media malfeasance as reminders of the risks:

I watched ABC FAKE NEWS this morning, both lightweight reporter Jonathan Carl’s(K?) ridiculous and biased interview of Tom Cotton (who was fantastic!), and their so-called Panel of Trump Haters, and I ask, why would I do the Debate against Kamala Harris on that network? Will panelist Donna Brazil give the questions to the Marxist Candidate like she did for Crooked Hillary Clinton? Will Kamala’s  best friend, who heads up ABC, do likewise. Where is Liddle’ George Slopadopolus hanging out now? Will he be involved. They’ve got a lot of questions to answer!!! Why did Harris turn down Fox, NBC, CBS, and even CNN? Stay tuned!!!

Or don't stay tuned, I guess, depending on the decision. 

This isn't the only reason why Trump may pull out of the debate. The New York Times reports this morning that the Harris campaign, which insisted that it inherited the deal Joe Biden made with Trump, now wants to change the rules that Team Biden negotiated. They want the microphones live throughout the debate now, an apparent nod to how well that ended up working out for Trump:

Now, Ms. Harris’s campaign is calling for a change to the original rules for that debate. Mr. Biden had asked for each candidate’s microphone to be muted when it wasn’t his turn to speak, and Mr. Trump agreed.

“We have told ABC and other networks seeking to host a possible October debate that we believe both candidates’ mics should be live throughout the full broadcast,” Brian Fallon, a spokesman for the Harris campaign, said in a statement, referring to the scheduled Sept. 10 debate and to an additional debate in October that the campaign has said it is open to negotiating. “Our understanding is that Trump’s handlers prefer the muted microphone because they don’t think their candidate can act presidential for 90 minutes on his own.”

Mr. Trump’s campaign responded by noting that it was Mr. Biden who requested the muted mics to begin with.

“ABC offered the exact same debate rules as CNN, and we accepted — as did the Harris camp,” a Trump spokesman, Jason Miller, said. “Now, after the Harris campaign has begun debate prep, they’re clearly concerned about what they’re seeing from Harris’ performance and want a whole host of rules changes.”

This sounds like better grounds for tossing the ABC debate. The only reason Trump stuck with this debate was because of that earlier agreement. If Team Kamala wanted to change the rules, then they should have reopened negotiation on all debates rather than claim that Trump was still bound to the original agreement. 

And this change in particular is very suspect; why would they want Trump's mic to remain live? They're probably wanting to get Trump to talk over Kamala so she can pull her "don't interrupt a woman" act that she used somewhat effectively against Mike Pence four years ago. If ABC turns his mic off, that doesn't work, and the focus will be on Kamala's answers ... or lack thereof. 

Still, Trump is better off having the debate, even with all of these problems. Trump can easily attack moderators who suddenly shift into propaganda mode -- excuse me, "fact checking" mode, nudge-nudge, say no more. That victimization stunt Harris pulled on Pence has zero chance of working with Trump, who will use it to ridicule her and steamroll her even further. The value in the debate will be forcing Harris to actually answer questions, which she won't do now, refusing pressers and even interviews with a besotted media clearly dying to toss her softballs. The debates may be the only opportunity Trump has to expose Harris as an empty suit in front of a national audience. 

That's worth a little headwind from ABC's propagandists, at least as a managed risk.