Robert Kraft’s name will now long be associated with one of the most despicable scourges of modern life, and rightly so.The New England Patriots owner is charged with soliciting prostitution at a Florida massage parlor busted as part of a sex-trafficking ring. Kraft denies it, although the police in Jupiter, Florida, say they have video evidence.The charges against him, and two other high-flying men from the financial world, represent an important front in the fight against sex trafficking. Authorities should be doing everything they can to crack down on the supply of trafficked women — via the networks that often import them to the U.S. and force them into prostitution — but also exacting a price from the men who constitute the demand.As Donna Hughes of the University of Rhode Island has written in support of a perpetrator-focused approach to sex trafficking: “The men who purchase the sex acts remain nameless, faceless, and uncharacterized. They are not stigmatized the way that ‘prost...