Donald Trump, who ducked debates during the Republican primary, now says he will debate Joe Biden “anytime, anywhere.” Biden, who also ducked debates during the Democratic primary and scrapped the final debate in 2020, now says he is ready to agree to debates: “Make my day, pal. . . . I’ll even do it twice.” I warned last fall that we shouldn’t assume any debates would happen this year, and that Trump ducking the Republican debates was forfeiting the high ground that could be used to make it costlier for Biden to back out. I will believe we are having debates when I see them. This race is between two very old men who struggle verbally. We have one candidate whose doctors don’t want him walking, and one whose lawyers don’t want him talking.

That said, there is political risk in appearing afraid to debate. The recent movement of the two candidates toward an agreement to debate suggests that both of them realize that they need to appear willing to debate the other. Also, the side that thinks it is losing knows that there is more risk in not debating, and Trump’s persistent leads in the polls have started to sink in enough to worry Team Biden. For now, the Trump campaign says that it has agreed to an initial debate on June 27 on CNN.

But consider the incentives to bail out. Start with the fact that the candidate who’s ahead won’t want to debate. Right now, that’s Trump. By the fall, it might be Biden. In the primaries, it was both of them. Either way, the incentive to debate drops on one side in proportion to how it rises on the other.

Sure, neither candidate will want to take the heat for just pulling out. But these are not exactly two candidates who have been unwilling to break norms in the past when they thought it would help them — Biden has some gall in hitting Trump for ducking primary debates when Biden did the same thing. Either will gleefully use some pretext to claim that the debate system was being rigged against them, and their supporters will eat it up. Moreover, both campaigns have thus far operated as if firing up their own supporters is the only thing in this election.

Even aside from the pre-existing Biden narrative that the president shouldn’t dignify his opponents with a platform, there will be no shortage of available pretexts, because both sides will be jockeying to control how the debates are staged. Biden has finally done what Republican campaigns have flirted with for years: he’s rejecting the role of the Commission on Presidential Debates. That means that everything about the debates — timing, moderators, rules, crowds, third-party access to the stage — will be negotiated directly between the two campaigns. The Biden campaign’s letter to the commission highlights several of the potential sources of disagreement. Consider:

I don’t weep for the Commission on Presidential Debates, which after all is just a conduit for the two campaigns and doesn’t have any real source of its own institutional legitimacy. But by discarding it, Biden has taken off the gloves in what is likely to be a bare-knuckles clash between the campaigns, as each grapples for a pretext to blame the other for the debates not happening.