Not that long ago, Marco Rubio was getting mocked for being too scripted and programmed as a candidate -- a victim of Chris Christie's ridicule in the New Hampshire debate, the subject of online cyborg memes, the target of protesters dressed in robot costumes.

Now in what may be the twilight of his campaign -- after an ill-fated detour through the gutter of campaign politics -- "Robot Rubio" has turned in the most human-sounding performance of his race for the nomination.

A 13-minute news conference Saturday where Rubio addressed the escalating violence and rhetoric at Donald Trump pep rallies went viral, coming off as one of the most convincing and most credible moments from a candidate in the Republican campaign so far. He was sad, his voice cracking. He spoke candidly. He appeared to be speaking from the heart.

On Saturday, following Trump's decision to cancel a rally Friday night in Chicago due to clashes between attendees and protesters, Rubio spoke to reporters about the rhetoric Trump has been using at his rallies, the responsibilities of being commander in chief and whether or not he'd vote for Trump if he becomes the nominee.

Rubio spent much of the news conference discussing how Trump's refusal to condemn violence -- and his language that could be inciting it -- is not leadership. "The job of a leader is not to stoke that anger," Rubio said, referencing the pent-up frustration shown at Trump's rallies. "The job of a leader is to address the causes of that anger and try to solve it."

A bit later, he said "leadership has never been taking people’s anger and using it to get them to vote for you" -- the very definition of demagoguery, by the way. "If it is, it's a dangerous style of leadership," he said. "Leadership is about acknowledging people's anger, but as a leader, trying to address why it is they're angry instead of manipulating their anger so they become your voter, your donor, your supporter."

Agree with him or not, he did a masterful job of acknowledging the anger Trump’s supporters feel without inflaming it. “Every major institution we once relied on is failing us,” he said, ticking through how religious organizations to higher education to politicians have all given people reason for frustration. What Trump is doing, Rubio said, is telling his supporters “give me power so I can go after them. That’s what he’s feeding into.”

But that’s not leadership, Rubio said — or at least, “that is not productive leadership. That is not good leadership. And it is not keeping with our American tradition. That is a style of leadership that says 'I know you’re angry and I’m going to take advantage of it so that you vote for me.' ”

It was repetitive, but it was also very effective. And it was not just what he said, but how he said it. Rubio came off as genuinely concerned and disgusted by Trump’s rhetoric. He seemed less to be speaking to the cameras than to be someone who just had to get something off his chest. He appears unscripted, authentic.

Whether it will do much for Rubio -- or in the results of the GOP primaries -- is unknown. It came late, a moment of honest reflection as a route to the nomination for him appears out of reach. Rubio is trailing Trump in the polls of his home state of Florida, which many see as his campaign's ultimate test. How authentic his remarks will sound if he ultimately does endorse Trump, or when held up against his recent schoolyard taunts, are both important questions.

Still it’s the kind of voice we should hope to hear more often if Trump continues to make calls to “knock the crap out of 'em” or say “I'd like to punch him in the face” about protesters. While Trump said on "Meet the Press" Sunday that "I do not condone violence of any shape" and on Monday that his rallies are "love fests" where there's "no violence," he is also issuing threats and deflecting responsibility. “The people are angry at that," Trump said Sunday. "They’re not angry about something I’m saying. I’m just a messenger.”

It’s deeply troubling to think how far back we’ve fallen since 2008, when John McCain campaign event told one attendee that then-candidate Barack Obama was not someone to be scared of, and grabbed the microphone from another woman who said "he's an Arab." "He's not," McCain said. "He's a decent family man citizen that I just happen to have disagreements with on fundamental issues and that's what this campaign is all about. He's not."

Leaders are not messengers. They are message shapers and problem solvers. They denounce violence wherever they see it. And they help people turn their anger into something productive for the future, rather than exploit it as a way to return to the past.

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