“Insanity: doing one thing over and over again and expecting different results.”

Albert Einstein is usually credited with that particular witticism. It’s a quote that has been trotted out by many the exasperated observer when confronted with foolish stubbornness. It’s used to implore the listener to abandon a lost cause — or, at the very least, to change their approach.

It’s a quote that many Republican elites ought to pay attention to when they strategize on denying Donald Trump the GOP nomination. In recent weeks, top Republican officials seem to have settled on a barrage of fundraising and anti-Trump ads as the best course of action in slowing the billionaire’s momentum.

Let’s try a brief thought experiment. Despite his inflammatory (to be polite) rhetoric, Trump is still the Republican frontrunner, by a large margin. If his campaign has any coherent message, it’s one of the anti-establishment, throw-the-rascals-out mentality. Trump has campaigned as the answer to the entrenched elites that have paralyzed Washington.

With that in mind, how exactly will a coordinated ad-blitz by rich establishment staples help tarnish Trump’s image? If anything, such an attack will only serve to reinforce his brand as an outsider feared by the political elites. He has already proved impervious to all conventional political wisdom. This is the candidate that called Mexican immigrants rapists and thieves, the candidate who said POWs weren’t war heroes, the candidate that made sexist jokes at Megyn Kelly’s expense — and saw a steady rise in his poll numbers each time. The establishment figures will bring their formidable weapons to bear only to find Trump utterly immune to their attacks.

So what? Do mainstream Republicans just roll over? Of course not, but Trump’s remarkable candidacy calls for equally out-of-the-box techniques. Lord knows I don’t have a perfect solution, but surely there must be some inventive politico out there with a trick or two up his or her sleeve.

Looking at the delegate counts, it seems the Republicans’ best hope is to host the first brokered convention in decades. Whether that will result in a Trump candidacy, a reasonable alternative, or — God help us — Trump declaring an independent bid for the White House. Only time will tell. One thing is for sure though, we cannot rely on the same tired old playbook. That’s what has gotten us this far already.