Rubio's repetitive repetition at the GOP debate last night strikes me as a sign that this not a man who is comfortable with public speaking or debate, at least under the bright lights. He had X phrases he wanted to be sure he got out, and, by God, he was going to get them out, even if he lost track of what he'd already said and simply grabbed for the next one that bobbed up in his memory.
Remember that this is also the same Rubio of the water breaks during his SotU response.
Now, not being good at standing under the bright lights and performing glibly is not necessarily a disqualifier for President. In some ways, in our overly polished politician-as-celebrity world, it's almost refreshing. But how one handles uncomfortable or challenging situations is informative — does one freeze up, babble, or soldier on — and something Republican voters should keep in mind during this primary season.
(I'm going to leave aside from this critique Rubio's rabid anti-Obama rhetoric; he's apparently decided the best way to win the nomination and beat Clinton is to run against Obama, and doing so in as knee-jerk a "Obama is out to destroy America" way as possible. We'll see how that actually works for him.)
Wow. This article details the Rubio repetitions and includes a longer video from the debate that makes him even less persuasive (http://www.slate.com/articles/news_and_politics/politics/2016/02/marco_rubio_was_a_disaster_in_the_gop_debate_on_abc.html). I am by no means a Christie fan (and I question his thesis about a short stint in Congress meaning someone is not qualified for the presidency — whether we are talking Obama, JFK, or Abe Lincoln), but he nailed it in identifying Rubio's far-too-shaky reliance on memorized speaking points.
To give Rubio credit (I guess), he is not backing down: http://www.rawstory.com/2016/02/marco-rubio-vows-to-continue-robotic-attacks-after-debate-beat-down-im-going-to-keep-saying-it/