Another presidential candidate floats a flat tax, but would it sink under its own weight? This time it’s GOP contender Rand Paul. He’d replace the tax code with 14.5 percent in federal tax on all personal income, including wages, investment income, and rents. He’d repeal the Social Security and Medicare payroll tax but tax wages at both the business and individual level. Over ten years, Paul’s plan would cut tax revenue by more than $2 trillion—maybe $3 trillion using more traditional calculation. That’s trillion, with a “T.” TPC’s Howard Gleckman considers the numbers: “Tax cuts of this magnitude would represent a sea change in how the federal government raises and spends money. An even bigger change, perhaps, than even Paul wants to acknowledge.” Speaking of reduced revenue: Inflation is draining the Highway Trust Fund. TPC’s Richard Auxier explains. The fund receives 85 percent of its revenue from the federal gasoline tax of 18.4 cents per gallon. The tax hasn’t changed since 1994, but its buying power has shrunk considerably. Adjusted for inflation, it is worth only 11.5 cents. Plus the cost of road and transit construction has increased. Ouch. Affordable Care Act developments… The House voted to repeal the medical device tax yesterday. President Obama vows to veto the bill. The 2.3 percent tax affects 7,000 manufacturers and raises $25 billion over ten years for the Affordable Care Act. House Speaker John Boehner, meanwhile, isn’t interested in extending tax subsidies under ACA if the US Supreme Court upends the law in its impending King v. Burwell decision: “We are not interested in protecting a fundamentally broken law. We have an obligation to do what our constituents ask of us.” Other Republicans would temporarily extend the subsidies but repeal the individual mandate. Also on the Hill… The House did not vote on the Export-Import Bank, the export credit agency of the US, and does not plan to before its charter expires on June 30. The Hill reports that lawmakers who back the bank might try to attach its charter renewal  to the must-pass (but almost certainly temporary) highway funding bill. But that measure probably won’t move until late July. And in case you missed it… You can see the presentations from yesterday’s IRS-TPC research conference here. It featured some of the latest research related to tax administration. Interested in subscribing to the Daily Deduction, the Urban-Brookings Tax Policy Center summary of the day’s tax news? Sign-up here to get the Daily Deduction delivered to your inbox every morning. If you’d like to tell us about a new research paper or have any comments about our feature, write us at [email protected].