IRS Commissioner Danny Werfel faced a grilling by lawmakers on Capitol Hill this past week, where he hinted that there's a chance that the agency will—contrary to its repeated pledges—increase tax audits of Americans earning under $400,000.The question of whether the IRS will use some of the $80 billion or so funding boost to increase tax enforcement of people making less than $400,000 has been a contentious issue.IRS and Treasury Department officials have pledged not to increase audit rates for this group of Americans, while Republicans and others have argued that this pledge is either false or wishful thinking.Treasury Secretary...