With the US economy on its knees, how to turn it around has unsurprisingly been the main theme of the Republican debate season. All GOP presidential hopefuls see transforming the tax code as a vital part of that mission. Roughly two months before voting starts, the race is still widely open as polls have been shifting and inconclusive and frontrunners and underdogs have traded places.

Herman Cain

The Tea Party darling and former chief executive of Godfather’s Pizza chain has sensationally become the frontrunner. Cain is proud of the fact that he is not a politician, “I’m a businessman, which means that I solve problem for a living,” he told the audience at the latest debate in Las Vegas. In Gallup’s latest probe, Cain is at 30 per cent, twice as much as any of the other conteders. He is now recognized by 78 per cent of Republicans nationwide, a gain of 28 percentage points since September and 57 points since March; the largest gain in recognition for any GOP candidate this year.

Part and parcel of his success has been his catchy 9-9-9-plan, which means 9 per cent income tax, 9 per cent corporate tax, a 9 per cent national sales tax, and the rest of the federal tax code would be scrapped. The federal income tax today stands at 35 per cent. The plan has proved so popular that it has forced his competitors to come out with more specific proposals, as well as attacking the plan from all angles.

Rick Perry

Texas governor Perry was a favorite even before throwing his hat in the ring, but the arch-conservative has been largely disappointing in the debates he has taken part in, and has fallen behind in the polls.  

Probably as a response to Cain’s concrete plan on tax, Perry recently said that he wants to give Americans the opportunity to “throwing out that three million words of the current tax code” and replace it with a 20 per cent flat income tax. Part of his plan is also to scrap the federal inheritance tax as well as taxes on qualified dividends and long-term capital gains.

In Las Vegas, Perry told Cain: “I love you brother…but go to New Hampshire, where they don’t have a sales tax and you fix to give them one. They are not interested in 9-9-9.”

Gary Johnson

Johnson, former governor of New Mexico, has also attacked Cain, and he argues that he does not go far enough: “The real problem with Herman Cain’s 9-9-9 plan is that it is an apologetic, timid step toward what America really needs in order to ignite our economic engine: replacing all federal taxes with one simple consumption tax, commonly known as the fair tax,” he wrote in an opinion piece in the Daily Caller.

However, Johnson, who has only featured in two out of eight debates because of his low ratings, does not have a policy on income tax. The most concrete in his tax plan is that he wants to eliminate corporate tax, as well what he calls “punitive taxation of savings and investment”.

Ron Paul

76-year-old Paul is a senator from Texas and an unashamed libertarian. He has a group of young and enthusiastic followers, and sticks out in GOP circles for being so strongly anti-militarism.

Paul is also the most radical candidate on economic policy, and not just for wanting to close down the Federal Reserve, but also because he wants to get rid of the income tax and replace it with nothing. As a self-proclaimed constitutional expert, he does not think that Congress should have the power to impose a direct income tax. To balance the books, the government should rely on excise taxes, non-protectionist tariffs but most importantly cut spending dramatically, especially on weapons and overseas activities.

“America without an income tax would be far more prosperous and far more free, but we must be prepared to fight to regain the liberty we have lost incrementally over the past century,” Paul says on his website.

Michelle Bachman

Foreign policy hawk and socially conservative to her fingertips, congresswoman Bachman is the voice of the Tea Party movement voice in the House of Representatives. She has made the repeal of Obamacare the cornerstone of her campaign, but the former tax lawyer has been vague on the tax code.

"My plan has not only a tax plan in it, but it’s a jobs and economic recovery plan,” she told Fox News earlier this month. “For my tax plan, I take a page out of one of my great economists that I admire, Ronald Reagan. And under my tax plan, I want to adopt the Reagan tax plan. It brought the economic miracle of the 1980s."

Part of Reagan’s tax revolution was to cut taxes for the wealthiest and median households. One of Bachman’s proposal is a national minimum tax, “even if would just be a dollar”, referring to all low income Americans who do not pay any income tax at all.