The lying. This one’s a problem on so many levels, but specifically to debating him there are at least two dynamics to contend with:

1. Volume: As we see every day, the sheer number of Trump’s lies overwhelms even the most diligent media outlets trying to fact check him. Doing so in real-time is all the tougher. So our nominee should know that Trump will lie throughout their debate, but can’t count on the moderator to call them all out and can’t expect the audience to know on their own. So our nominee needs to be able to say, “You’re lying.” Easier said than done. Especially if Trump lies every time he opens his mouth.

One possible tactic is to simply, and calmly, count out loud. First time he lies, the nominee should say, “That was the first of many lies to come because that’s what he does best.” After that, when Trump lies again, the nominee should interject with a simple “Lie number two,” or, “That was a few, so we’re up to six.” The moderator might scold the candidate for interrupting, but he or she should respond, “If you were calling out his lies, I wouldn’t have to. But someone has to. He gets away with it all day every day. But not here, not now.”

2. Target: A good chunk of Trump’s lies will be about the nominee prior to the debates, and to their face during the debates. Even a grizzled and jaded politico like me would never suggest the answer to this problem is to lie about him. Just stick with the truth—it provides more than enough fodder.