Rand Paul has got a deal for you. Photo: Ethan Miller/2015 Getty Images

Keeping your place at the radical cutting edge of the Republican Party is a challenging task in a world where a “mainstream” candidate like Marco Rubio proposes to eliminate all taxes on investment income. Rand Paul places his bid by unveiling his trademark plan today: a 14.5 percent flat tax.

To design his plan, Paul has assembled an all-star team of the kookiest pseudo-economists in the history of the Republican Party. Steve Moore, Steve Forbes, and Art Laffer all helped dream up the specifications. (Laffer is fresh off advising Sam Brownback on a program of tax cuts in Kansas, which left the state’s budget a smoking ruin and reduced Brownback to tears.)

Paul argues in a Wall Street Journal op-ed that his plan is necessary to save America from imaginary scandals. “We now know that the IRS, through political hacks like former IRS official Lois Lerner, routinely abused its auditing power to build an enemies list and harass anyone who might be adversarial to President Obama’s policies,” he writes, “A convoluted tax code enables these corrupt tactics.” In fact, we now know that nothing resembling Paul’s account took place, and that the IRS investigated electioneering by nonprofit organizations without regard to their support for or opposition to Obama. What’s more, even if Paul’s imagined scandal did take place, a flat tax would do nothing to prevent it, because as long as taxes exist, some law-enforcement agency will have the power to investigate people who are supposed to pay them.

Paul’s plan would give rich people an enormous tax cut, while keeping in place the home-mortgage deduction, the largest, most regressive, and most economically damaging deduction in the tax code. It’s okay to give rich people an enormous tax cut, he explains, because “the experts at the nonpartisan Tax Foundation” — a hackish right-wing outfit — deem it, in Paul’s words, “an economic steroid injection,” which sounds like an amazing shortcut for growth without any noxious side effects at all.