Presidential candidate Marco Rubio first became publicly associated with water back in 2013, when he interrupted his response to President Obama’s State of the Union address to sip from a cup of the stuff. Since then, the public probably hasn’t thought much about Rubio’s drinking habits (despite Donald Trump’s occasional bullying), but the reporters assigned to follow Rubio around the country have, as evidenced by Politico’s deep dive into the Florida senator’s commitment to hydration.
Rubio reportedly requires a stemless glass of water (“not stemmed ones or water bottles”) whenever he gives a speech, and becomes visibly anxious when forced to go without. “Marco does have a water thing,” a “longtime associate” told Politico. “I don’t know what it is. He says he just gets thirsty, but it’s clear it’s just a nervous tic. It’s something he just has to have around, like a security blanket or something.” Like many people with nervous tics, the Florida senator often jokes about his “water breaks,” which observers likely find either endearing or uncomfortable, depending on the sort of personalities they have.
More damningly, Rubio’s “water thing” might just be part of a larger body-temperature regulation issue:
But people who have worked with Rubio said sweat has also been a distraction for him. “You hear Donald Trump make fun of him for it. But he’s on to something,” said Rubio’s longtime associate. “I don’t think Marco sweats that much more. But Marco thinks he does. He’s always wiping, wiping, wiping sweat — even if he’s not sweating. It can drive you crazy if you’re watching him closely.”
The person who has staffed CPACs at which Rubio has spoken agreed with Trump’s assessment. “He sweats quite a bit and when you sit down under television lights it gets very hot,” said the person, who recalled the issue arising when Rubio did not have water during his speech at the 2012 gather. “Not only was he very thirsty but he was under very bright lights … Beads of sweat were just popping up on his forehead.”
There’s even more about this here. As far as “things to be self-conscious about” go, Rubio would probably rather you focus on the water than on that other stuff.