Donald Trump advised his Republican opponents to stop going negative because every time a candidate has attacked Trump, that candidate falls in the polls. As always, The Donald is right. Ask Jeb Bush, Rick Perry, Rand Paul, Lindsey Graham, and Scott Walker how attacking Donald Trump has worked out for them. The polls speak for themselves:
The data having established that any candidate who attacks Donald Trump will inevitably fall significantly in the polls, we might ask: How would Trump fare in a hypothetical matchup with Hillary Clinton, assuming she doesn't lose the Democratic nomination for being a criminal? She will be forced to attack The Donald, won't she? She will.
Trump wins. He always does.