There are many things to like about Jeb Bush’s new tax reform proposal, including its overhaul of the corporate income tax, its expansion of the earned-income tax credit (EITC) for childless workers, and its limits on tax expenditures for high-income households. But one of its provisions in particular has been unjustly neglected, and I’d like to see other Republicans champion it. In many two-earner married households, one earner earns substantially more than the other. Say a man who makes a modest income as a teacher marries a woman who earns a high income as a corporate attorney. By getting hitched, he will pay a higher marginal tax rate than he would have had he remained single. The same might be true of his wife, if their combined income bumps her up from one marginal tax rate to another. Jeb proposes allowing the lower-earning member of a couple to file a separate tax return. This would eliminate the marriage penalty for millions of households and it would create a much stronger work incentive. And because most second earners are women, this provision could be the linchpin of a broader effort to ease the economic burdens facing working women, including working mothers. Though I doubt that this one measure will give Jeb’s campaign a shot in the arm, I do think that the next Republican presidential nominee will have to win over middle-class women by appealing to middle-class economic interests. Getting behind separate filing is a good start.