From Democratic polling firm Public Policy Polling in a survey on potential 2016 presidential candidates:
Marco Rubio continues to lead nationally [among Republicans], as he has on all four of our 2016 polls so far. He's at 21% this month, basically the same as 22% the month before the State of the Union address. Rubio's favorability of 62/10 is slightly better than 59/12 in early February. The whole water drinking episode hasn't had any effect on his standing- nor has his stance on immigration reform.