Their Better Halves? - NYTimes.com You know the political season is heating up when the spouses begin appearing here, there and especially on television talk shows, and last night we had a twofer: on "Piers Morgan Tonight," Karen Santorum, who assured us that Rick won't trample over women's freedoms as much as he sometimes seems to itch to, and on "The Late Show with David Letterman," Michelle Obama, who told us how exceedingly intelligent Bo, the first Portuguese water dog in the White House, is. Yes, I'm being a bit snarky. But that's only because I find the way political spouses are deployed and discussed to be so very silly at times. Every campaign asserts, with seemingly genuine conviction, that the mere stepping of a spouse into the spotlight "humanizes" the candidate. To which I say: how? We already knew the candidate was married. Getting married is hardly an extraordinary thing (unless you're homosexual, in which case it's still illegal in 42 of the 50 states). A spouse's warmth, eloquence and whatever other virtues he or she possesses belong to, and flatter, him or her: they're not loaners, their ownership transferrable to the other partner via a quick spin on "The View." The candidate remains the candidate, with the same shades of grace or clumsiness or brilliance or idiocy that existed before. Be that as it may, the spouse is almost always called a "secret weapon," a phrase worn to the nub, as I noted in a column late last year. Just as reliably, there's impressed talk in the news media about how much more popular than the candidate the spouse is. Of course the spouse is more popular: he or she isn't casting controversial votes in the state house or the U.S. Congress! He or she isn't saying "I approve this message" at the end of hideously negative ads. He or she didn't flat-out promise certain legislation, only to have it watered down, mired in committee or postponed until some far-away day when polarization ebbs and sanity flows. He or she isn't firing off nasty barbs in televised debates, though I'm not saying I'd be against a debate between would-be first ladies (or laddies), which sounds to me like an enormous deal of fun. I'm just saying I haven't noticed one in my lifetime, and I'm not holding my breath. Michelle Obama's visit to "Letterman" was a perfect case in point. While she was immensely charming and eloquent on the subjects of both military families" challenges and the epidemic of childhood obesity, she didn't stake out a single risky or bold position. Among public health officials wondering how to put some teeth into efforts to get kids off sugary sodas, there are proposals to tax such sodas. There's serious debate about tightly regulating what people can use food stamps to buy. There's talk about finding new ways to apply pressure to supermarkets in terms of what they stock and how they display it. But these are all ideas that prompt spirited disagreement and outcries from important lobbies. They're tough terrain. And as the first lady talks - sensibly and rightly - about getting kids away from the television and into yards and parks, she tends to steer clear of that ground. She certainly did last night, avoiding anything that might step on this kind of headline, from USA Today: "Michelle Obama nearly tears up with David Letterman." That's undoubtedly wise. And it's absolutely her prerogative. And it's wholly in line with the largely apolitical behavior of most of her predecessors in the White House. But that sort of delicate sidestepping is also the main reason that she and other first ladies who have practiced it have enjoyed such high approval ratings. And it's why those ratings have limited meaning. We in the news media, always eager for a new face to home in on and a fresh narrative thread to tease out, like to mull the significance of the spouse. But except in extreme cases, I don't think a spouse has much influence on votes. Have you ever been on the fence between two candidates, and had your vote swung by what you thought of the candidate's spouse? I ask that earnestly. Your account of that would make for great reading.