A chastened Republican field took the stage Thursday night in Miami, determined to focus on substance and policy without personal attacks or discussion of hand size.

It only benefitted the front-runner.

Senators Marco Rubio and Ted Cruz and Governor John Kasich did their best to underscore their policy acumen and to highlight Donald Trump’s lack of substance.

It backfired.

Neither his opponents on stage nor the debate moderators laid a glove on Trump.  When Trump repeatedly called Putin a “strong leader” without refusing to place a value judgment on his leadership, neither moderator Jake Tapper nor his opponents on stage pressed him.  When Tapper asked Trump about his violence-inciting rhetoric at rallies, none of Trump’s opponents called him out for refusing to disavow it. 

There is no bigger indicator that Trump’s opponents on stage were simply going through the motions.  Trump spent the night running down the clock and the remaining candidates spent the night checking the boxes. For at least two of them, this was their last chance to distinguish themselves in advance of what will likely be the most crucial primary day of the cycle next Tuesday. 

Rubio, in particular, seemed most chastened by his earlier decision to get in the gutter with Trump. Gone were the snide remarks about genitalia, orange makeup and pants wetting.  Instead, Rubio seemed to be playing for his political legacy by focusing on the issues.  He did not make a particularly solid argument for why he should win the Florida primary next Tuesday but he did make a strong case for salvaging what was left of his reputation as an adult.

This debate was the most substantive of the cycle, even if the substance was often wrong.  But what does it matter when facts are wrong, if everyone played to type? 

Did Trump know that it is false to claim, as he did, that “GDP was zero, essentially, for the last two quarters” or is he so ignorant of the facts that he did not realize that GDP had risen during that time period? 

Did Rubio know that it would be impossible to balance the federal budget if he were to provide the tax cuts he has promised and increase military spending by the amount he has pledged?

It seemed at times that the debate veered towards what passes for substance because Trump’s opponents had tried every other tool to bring him down and all that remained of the kitchen sink was civility and substance.

Barring all else, Cruz and Rubio took a tool out of the Kasich playbook and tried to kill Trump with kindness. They realized, belatedly, that Trump has dined on their negativity and has been strengthened by their attacks.  But at this late date, with the prospect of Florida and its 99 delegates looming large, their tactics looked more like a Hail Mary pass than a well-thought out plan to stop Trump from the nomination.

Julie Roginsky has extensive experience in government, politics and public relations on both the federal and state levels. She is the president of Comprehensive Communications Group, a public relations and crisis communications firm that counts Fortune 500 corporations, elected officials and non-profit organizations among its clients. Follow her on Twitter @JulieRoginsky.