What Cruz is demonstrating, as Gingrich did, is the ability to weave any answer to any topic into a broader argument that resonates with the Tea Party and evangelical wings of the Republican Party, and that embodies the sense of resentment and disaffection that has propelled Donald Trump into a status almost no political observer imagined. It is of a piece with Cruz’s fundamental campaign approach, which fuses highly specific, almost wonky-sounding policy points and broader populist themes that resonate with even the most policy-averse corners of the Republican electorate.

This is no guarantee that he will wind up as the GOP nominee, or that if he does, he will find a ready audience in the broader electorate. There are plenty of grounds to see in Cruz a very skillful demagogue, and there are plenty of debates left in whichh a rival might find the weaknesses in his argument, just as Mitt Romney unhorsed Gingrich just before the key Florida primary in 2012.

But here’s a bit of advice to those who would find a Cruz nomination or presidency a disaster: The single biggest mistake that is made in politics is to underestimate an adversary.