...The SEC is investigating Mr. Frist for unloading his shares of hospital chain HCA prior to a July earnings warning. Democrats are suggesting that an HCA insider gave Mr. Frist a call to tip him off. Mr. Frist denies it, and to date there is zero evidence... to support the allegation. And nothing in Mr. Frist's past or character suggests he's the kind of politician who'd try to scam the system.... The real issue here is the modern demand that politicians abandon all acquaintance with the world of commerce when they take office, lest they have a "conflict of interest."...