TAMPA—Ann Romney got a very warm reception inside the convention hall here Tuesday night. And, after a shaky start, she gave as good a speech as the Romney campaign could probably expect of her—political spouses deserve to be scored on a generous curve when it comes to giving high-pressure, prime-time speeches, a feature of our system that strikes me as beyond the call of duty. “You can trust Mitt,” she told us over and over, implicitly comparing the nation to the 15-year-old girl she was when Mitt gave her a ride home from the night they met. It was a rather odd analogy—will he kiss us on the second date?—but it clearly was deemed necessary in the service of “humanizing” her husband, the utmost priority for this convention week. (Never mind the inconvenient remark made earlier in the day at a Pennsylvania delegation breakfast I attended by GOP pollster Frank Luntz, ostensibly in reference to Al Gore: “If you have to assert you are human, there’s no way you are going to be elected.”)

But it strikes me as unlikely that Ann Romney will be able to shoulder the load of making her husband more personally appealing to the electorate. Why? Because Ann Romney is not exactly the ideal messenger herself. Ever since Mitt Romney arrived on the national stage six years ago, there has been an assumption in the press corps and punditocracy that she is vastly more natural and down-to-earth than her husband. But it’s not hard to be more at ease on the stump than a man who likes to recite “America the Beautiful” and looked visibly uncomfortable simply standing and looking on after his arrival here tonight; Ann Romney’s relative superiority on this score has been inflated into an absolute claim to her personal appeal that I suspect is overstated with many voters.

The Atlantic’s Molly Ball already touched on one aspect of the real Ann Romney: a notable hardness that makes her an unlikely candidate for the work of softening Mitt.

Watching Ann Romney on the political stage, what she projects is not “softness” at all but a tough, hard-edged, even aggressive attitude. During her husband’s last campaign, “there were times when I wanted to like come out of my seat and clock somebody,” she mused on Fox a couple of years ago, according to an excellent profile in the Los Angeles Times. Earlier this year, she joked that she could “just strangle” the press sometimes. These aren’t serious threats of physical violence, but they reveal a combative side to her personality that’s at odds with the sweet, nurturing, maternal caricature.

Back in April, when Democratic strategist Hilary Rosen called her resume into question, Romney told a guests at a fundraiser that she relished the opportunity to defend her family. “That was a really defining moment, and I loved it,” she said. Far from playing the poor, injured martyr, she appears to enjoy a fight. In interviews, she’s more likely to push back than demur when pushed on issues like her family’s tax returns. “Have you seen how we’re attacked? Have you seen what’s happened?” she said to such a question on NBC earlier this month. “We have been very transparent to what’s legally required of us. But the more we release, the more we get attacked.”