Start at the intuitive level. Despite what you may have heard, true belief is pretty common among politicians. Listen to Rand Paul talk about liberty or Marco Rubio dilate on the promise of America; watch Bernie Sanders rail against inequality or President Obama defend technocratic liberalism. They all radiate sincerity. Watch a Goldwater speech: you can tell the man believed it.

With Cruz, though, even the most fervent peroration always feels like a debater’s patter, an advocate’s brief — compelling enough on the merits, but more of a command performance than a window into deep conviction.

This doesn’t mean that Cruz’s conservatism isn’t sincere. But the fact that he seems so much like an actor hitting his marks fits with the story of how he became Mr. True Conservative Outsider in the first place. Basically, he spent years trying to make it in Washington on the insider’s track, and hit a wall because too many of the insiders didn’t like him — because his ambition was too naked, his climber’s zeal too palpable. So he deliberately switched factions, turning the establishment’s personal disdain into a political asset, and taking his Ivy League talents to the Tea Party instead.

Then once installed as a leader of the counterestablishment, he walked a line that looks, again, far more calculated than most conviction politicians. While his fellow Tea Party senators, from Paul to Rubio to Utah’s Mike Lee, built detailed policy portfolios that fit their interests and inclinations, Cruz never seemed to take a step on any contentious issue without gaming it out 17 moves ahead.

His push for the Obamacare shutdown, and the bill of goods he sold the party’s base, was a particularly remarkably exercise in self-serving political cynicism. But on many fronts — Edward Snowden, trade policy, immigration, the fate of Middle Eastern Christians — Cruz has proceeded with several fingers in the wind; every time the conservative mood has shifted even a little, he’s shifted quickly too.