This week, the Florida senator is the butt of an eruption of social media jokes that were showing no signs of evaporating Wednesday following an awkward, televised lurch for a bottle of water during his response to President Barack Obama's State of the Union address.
A look of panic flashing across his face, an apparently parched Rubio lunged mid-rebuttal for the bottle — unfortunately placed just beyond his easy reach — while keeping his eyes fixed on the camera.
The desperate need to quench his thirst came after the senator, who'd already mopped his brow several times, had displayed audible signs of suffering from dreaded cotton-mouth.
It didn't help matters that the bottle was comically tiny. Rubio took a quick guzzle — looking into the camera all the while — before continuing with his rebuttal as a television audience of millions watched the startling spectacle unfold.
It took mere minutes for the fun to begin on Twitter, Facebook and on various websites and blogs.
There were Twitter hashtags, new Twitter feeds, steady loops of Rubio's frantic, thirsty mission, and even a slow-motion version of the clip on the website Deadspin, set to the indie song "Danger of the Water" by the Futureheads.
But there was precious little mention of the actual contents of his 14-minute speech, delivered under the hot glare of television cameras in a step into the national spotlight that was meant to underscore Rubio's gravitas as a rising Republican star.
His remarks, delivered after he made the same speech in Spanish, were perfectly serviceable compared to Republican rebuttals of recent years — those of Bobby Jindal and Michele Bachmann, after all, were cringe-worthy for reasons that had nothing to do with a sudden insatiable thirst.
But Rubio's need for water overshadowed his criticisms of Obama's economic proposals.
Was this Rubio's Howard Dean Scream? Dean's political aspirations suffered a near-fatal blow in 2004 when he delivered a throaty, emotional concession speech during the Democratic primaries.
Most observers don't think Rubio's lunge for water is comparable. The senator, they say, is instead deftly turning lemons into lemonade while his national name recognition goes through the roof.
"Let he who has never been thirsty cast the first bottle," said Jack Pitney, a politics professor at Claremont McKenna College in California and an academic authority on the Republican party.
"It's hard to imagine anybody holding it against him that he drank water. And now they know who he is."
And unlike many politicians before him, Rubio swiftly joined in on the fun, tweeting a photo of the bottle of Poland Spring water right after the rebuttal with the hashtag: #GOPresponse.
On Wednesday, a cheerful Rubio made the rounds of the talk-show circuit while clutching a bottle of water — and occasionally sipping on it.
"I needed water — what am I going to do?" he told ABC's "Good Morning America," pausing for another sip as he beamed good-naturedly. "It happens. God has a funny way of reminding us we're human.”
He added on Fox News: "When you give a speech on a podium, the water is right there. But when you don't, you start looking around thinking: 'Where am I going to get the water?'"
Pitney said Rubio's handling of what some wags have slyly dubbed "Watergate" struck exactly the right tone, all but ensuring the incident won't come back to haunt him should he make an anticipated run for president in 2016.
"Self-deprecation and humour go a long way," Pitney said.
"Those who follow politics closely might remember the water bottle, but for the average citizen, I don't think Rubio's got anything to worry about."