Considered almost unthinkable just five weeks ago, Trump’s appearance at center stage is now the most inconvenient of truths for the would-be Republican front-runners. From Milwaukee to Miami, campaign aides are already wrestling with the Trump factor — strategizing on how to engage with him (if at all) and how to stave off his attacks.
“He might be the only person on that stage with nothing to lose,” said one senior Republican campaign adviser, “and he isn’t going down alone.”

At the same time, candidates will be eager to ensure that they aren’t just playing bit parts in a two-hour Donald Trump show. That will be especially challenging given the feverish media attention surrounding the notoriously braggadocious front-runner.

“Unless everything changes in the next two weeks, which is always a possibility, I imagine Trump will be pretty much the top five stories of the debate just by showing up,” said Mark Leibovich, the chief national correspondent for The New York Times Magazine.