It wasn’t the slurp; it wasn’t the sudden downward lunge to grab a water bottle, as unique in the history of very important speeches as that maneuver was. It was the furtive look on Marco Rubio’s face as he tried to keep his eyes facing the camera between each of his quick-sneak glances off-stage—as if he were a kid playing peek-a-boo, and we weren’t supposed to notice him when he couldn’t see us.

The Poland Spring moment is going to be the only thing remembered about the Republican response to Obama’s 2013 State of the Union speech because it confirms a larger impression: First, Rubio seems really young, with that soft voice and those baby-fat cheeks. Especially when compared to the graying, emphatic Obama. Republicans who try to appeal outside the rock-ribbed base seem to have a recurring Kenneth the Page problem.

And Rubio’s furtive back-and-forth with the camera mirrors the trouble the GOP has as it oscillates between the image it wants to project and reality. A young fogy like Rubio is supposed to exemplify the new, youthful, Latino- (and even Tupac-) friendly face of the party, even as he spouts the same old soak-the-poor economics that his Latino-, black- and youth vote–suppressing base just can’t quit.

For all the elders’ (and the media’s) hopes that Rubio will be the GOP’s Obama, Obama never had to bridge a chasm that deep.

Still, you couldn’t help but feel for the guy. Time magazine did Rubio no favors by slapping him on the cover and declaring him the “The Republican Savior,” only to have party handlers push him out in front of a camera with no podium and a tempting bottle of water just out of easy reach. (Where are all those overpaid, high-production-value political consultants this time of the year?)

Maybe Rubio was nervous because he was speaking words that (1) he may not really believe, and (2) even if he does believe them, are so contradictory as to make no sense at all. “More government isn’t going to create more opportunities. It’s going to limit them,” he said—while several breaths later he admitted that he couldn’t have gone to college without government assistance and that retirees in his own working-class neighborhood “depend on Social Security and Medicare.” That’s like trying to walk and chew gum with your knees.

Dry mouth and flop sweat don’t always indicate that one isn’t telling the truth, of course. But consider the magnitude of Rubio’s assignment. As Paul Krugman puts it:

Faced with overwhelming, catastrophic evidence that their faith in unregulated financial markets was wrong, [Republicans] have responded by rewriting history to defend their prejudices.

This strikes me as a bigger deal than whether Rubio slurped his water; he and his party are now committed to the belief that their pre-crisis doctrine was perfect, that there are no lessons from the worst financial crisis in three generations except that we should have even less regulation.

The only hopeful sign is that—unlike Rand Paul, who gave the Tea Party response without a glitch—Rubio did the oral version of a blink. He gulped.