To gear up for her first national debate against Republican nominee Donald Trump, Hillary Clinton is reportedly holing up at her home in Chappaqua, New York—studying briefing books on her opponent’s policy proposals and general temperament and consulting Tony Schwartz, co-author of Trump’s much-toted 1987 bestseller The Art of the Deal.

But if Trump has demonstrated any consistency this campaign cycle, it’s that he’s a patently inconsistent candidate. In the ’80s, Trump mastered the art of the deal. In 2016, it’s all about the art of unpredictability. If the stakes were than the White House lower, it might be legitimately entertaining—Trump might tread where no major-party candidate has gone before. Whereas nominees in the past have traded barbs primarily centered on policy standpoints, with a few dogwhistle ad hominems sprinkled in, Monday’s debate between Trump and Clinton might be the first to go full throttle at personal attacks.

Trump’s Twitter exploits, per usual, indicate he won’t be holding back, perhaps even when it comes to Clinton’s health (traditionally an off-limits topic, at least in explicit terms):

But the worst thing Hillary Clinton can do, it seems, is respond in kind. The Democratic nominee has enjoyed her highest polling numbers of late following the Democratic National Convention in Philadelphia, Pennsylvania over the summer. That was an event centered primarily on an attitude of positivity and hope—standing in stark contrast the Republican convention, mired in anger and fearmongering. Trump spent that week bickering with the parents of a fallen Muslim-American soldier, and his numbers plummeted.

Monday’s debate offers Clinton an opportunity to replicate her post-convention bump. The polls have it: When Clinton stays positive and Trump goes uber-negative, she comes out on top.