The key moment came early in the debate, when Bush accused Rubio of shirking his responsibilities to his constituents
, suggesting that he ought to resign. Rubio shot back that Bush hadn't been critical of John McCain's 2008 presidential run, which had seen the Arizonan senator missing numerous Senate votes.
On one level, this was a clever response by Rubio (and probably one he had ready in advance -- Bush had telegraphed the attack in interviews before the debate).
The response allowed the Florida senator to attack Bush for attacking him (in the world of politics this somehow makes sense). And, having established that Bush did not really have a problem with absentee senators, Rubio stated that Bush only brought the issue up because he wanted to score political points. Rubio then pivoted to the high ground, suggesting that he himself is only interested in attacking Democrats.
Yet despite the plaudits, Rubio's response was actually pretty terrible.
The first and most obvious problem with Rubio's answer is that it was no answer at all. Pointing out that "everybody else does it" is more a childish retort than a valid explanation. If the senator worked for a company and his supervisor criticized him for not showing up, would it be sufficient for him to answer that other employees had missed work in the past and no one had said anything?
Whether he likes it or not, Rubio agreed to be the voice for Florida residents on the floor of the Senate. But keep in mind that Rubio was often absent from the Senate even before he announced that he was running for president.
For example, in 2014, Rubio missed 36 votes
, or about one out of every 10 votes that were taken. In comparison, Rubio's fellow senators on the main debate stage, Ted Cruz and Rand Paul, missed, respectively, 28 votes and 7 votes.
Even as the campaign has heated up for all the candidates, Rubio's absences have still outstripped those of his colleagues -- Rubio has missed over half of the 76 votes that have occurred since the start of July. In comparison, Ted Cruz has missed just under a quarter of the votes, and Rand Paul about 15% of them.
This should matter to Republican voters, who have been throwing their support behind nontraditional candidates such as Donald Trump and Ben Carson largely out of fatigue with the "political class." Those who are in the government are thought to be out of touch with everyday Americans. What better evidence could there be of this that politicians -- and senators being paid $174,000 per year
-- can simply decide they are too busy with other things to turn up to work?
Rubio's chronic absence from Senate votes is also directly tied to his biggest weakness as a candidate: his thin and completely political resume.
Rubio is a career politician -- a "man in a hurry," as one of the moderators prefaced a question on Wednesday -- and so his only real argument for higher office is his brief performance in his current and previous offices. True, Rubio did serve as speaker for the Florida House of Representatives. But this hardly seems adequate training to be the next leader of the free world.
So Rubio's incomplete Senate term is what we have to judge him on, including all those missed votes.
Of course, his defenders will note that from 2011 until 2013, Rubio missed only about 5% of votes, but this is still above the median of less than 2% for all senators now serving, and it doesn't change the fact that Rubio missed 36 votes last year, presumably as he geared up to run. In contrast, in 2006, the year before launching her first campaign for president, Hillary Clinton missed only four votes, while her opponent for the nomination, Barack Obama, missed only three votes.
If Rubio had been in the Senate longer, perhaps 2014 could be dismissed as an anomaly. As it stands, however, it is nearly a quarter of the record that we have for him. It is therefore understandable that other candidates might want to make this an issue during the primaries.
Next Tuesday, during the next Republican debate, Sen. Rubio's colleagues will have an opportunity to challenge him again. Let's see whether they do a better job of it than Jeb Bush.