My colleague John McCormick dives into the latest Bloomberg Politics/Des Moines Register Iowa Poll today to examine the reason for Donald Trump’s powerful appeal: he’s been able “to sell himself as the straight-talker most candidates aspire to be,” which has landed him squarely in first place.

This is an important insight that I’d carry further, because I think it explains why standard-issue Republican candidates such as Wisconsin Governor Scott Walker, who have tried to emulate Trump, typically fail and will always fail. Calling someone a “straight talker” is code for saying they’re authentic. Trump’s authenticity, and hence his appeal, stems from his willingness to criticize his own party’s priorities (tax and entitlement cuts), not just Democrats’, whereas most pols like Walker who style themselves straight talkers tend to limit their “straight talk” to criticizing the other party’s agenda and wilt when presented with a chance to critique their own side. Voters pick up on this and respond accordingly.

Over at the Washington Post, Greg Sargent seizes on a great example of Walker totally dodging an invitation to deliver some straight talk, when CNBC’s John Harwood asks him about the upward redistributionary effects of his health-care plan. The Trump answer would be something like: “You’re darn right, my plan takes money from the moochers and losers and returns it to the rich.”