Matt Lewis is making too much of the reaction to Rubio’s “age of the earth” answer:

And so, this is a strategy. Like Sarah Palin in 2008, Democrats view Marco Rubio as a major threat — not just for one or two elections — but someone who could undermine their advantage among the college educated, the young, and Latinos. Like Palin in ’08, he is viewed as an existential threat.

And just like Palin — whom they feared — they wan’t to destroy his credibility; to make him a joke.

This is all very flattering to Rubio, but I don’t think it’s true. It could have been anyone on the right giving this answer (which was a terrible answer), and the reaction would have been similar. Rubio may receive more scrutiny than most other Republicans because movement conservatives have worked overtime to promote him as a leading national figure, but not that much more. Judging from some of the reactions to his foreign policy statements in the past, he generally seems to receive no more scrutiny than other Republicans and may receive even less. I don’t believe that Democrats perceive Rubio to be an “existential threat” to their current advantages with any of these groups for the simple reason that he is unlikely to be very appealing to any of them. Are most young or college-educated voters clamoring for a more hard-line foreign policy? That doesn’t seem to be the case. In addition to the many other issues dividing Rubio from most Hispanic voters, it seems likely that his foreign policy views would be more of a significant liability with them than an advantage.

Rubio isn’t an “existential threat” to Democratic advantages with these groups for the same reasons that he doesn’t represent a solution to the GOP’s weaknesses with them. Like Paul Ryan, Marco Rubio makes a lot of pop culture references, but those references tend to date him and don’t endear him to most younger voters. The same views that make most movement conservatives into fans of Rubio put him at odds with these other groups. Because movement conservatives greatly exaggerate Rubio’s broader appeal, there is a temptation to see any criticism of Rubio as an effort to sabotage the GOP’s great electoral hope of the future. The reality is that Rubio doesn’t appeal broadly to people outside the GOP, which makes efforts to undermine his credibility with people outside the party unnecessary.