If you believe Bret Baier, and why wouldn’t you, something really was in the works — maybe not a traditional debate, but a town-hall forum or something along those lines. Apparently a donation to charity, as Trump had requested yesterday, was also on the table. Team Bernie had already issued a statement of its own claiming that two different networks had offered to host it and that a “major contribution to charity” was part of the deal. Trump, as I argued yesterday, had every reason to do it, from humiliating Hillary by elevating her challenger to lending Sanders some free buzz ahead of the California primary, where a Bernie victory would deliver another heavy PR blow to Clinton, to seizing an opportunity to pander to Bernie voters directly.

Sorry, no deal, said the Trump campaign in a statement written in fluent Trumpese.

Based on the fact that the Democratic nominating process is totally rigged and Crooked Hillary Clinton and Deborah Wasserman Schultz will not allow Bernie Sanders to win, and now that I am the presumptive Republican nominee, it seems inappropriate that I would debate the second place finisher. Likewise, the networks want to make a killing on these events and are not proving to be too generous to charitable causes, in this case, women’s health issues. Therefore, as much as I want to debate Bernie Sanders – and it would be an easy payday – I will wait to debate the first place finisher in the Democratic Party, probably Crooked Hillary Clinton, or whoever it may be.

Embarrassing Hillary by debating the second-place finisher is the whole point. He could have introduced Sanders at the event as the “real” winner of the Democratic primary but for the rigged system that’s in place. That would have been further common ground between Trump and Bernie fans. And as Damon Linker notes, there’s plenty of common ground already:

Viewers of a Trump-Sanders debate are just as likely to be presented with contrasting visions of how each of the nation’s two major parties might be rebranded as a “worker’s party,” addressing the concerns of the ordinary voters who feel so alienated from the status quo. In Sanders’ vision, the federal government would step in with massive amounts of spending on both old and new social programs. In Trump’s vision, protection for old programs would be combined with harsh restrictions on immigration and other forms of economic, political, and even ethnic nationalism.

I don’t know for sure which of these options would prove more potent in November if voters were given a choice between them (though I have my suspicions). But I do know that placing them alongside each other on a debate stage would only increase the likelihood that a substantial number of Sanders supporters will shift over to the only available populist option in the general election instead of voting for the candidate of the Washington establishment.

That’s precisely why Trump should want to do it, yet here he is backing out despite the networks apparently being willing to meet his charity demand, which increasingly seems like it was mentioned in the first place only because Trump thought they’d never comply and he could use their refusal as a pretext for backing out of his offer. (That wouldn’t be the first time he’s used charity as an excuse for dodging a debate.) I don’t know what other conclusion to draw, given how much sense it makes strategically for him to do it, than that he thought Bernie would embarrass him onstage. Or that Trump pandering too eagerly to Sanders’s fans would convince still-wary conservatives that he really is the Democrat anti-Trumpers have been accusing him of being all along.