Herman Cain will not be the only major Republican candidate for the White House with a sweeping tax reform plan, as Texas Gov. Rick Perry said on Wednesday that he will soon unveil a proposal for a flat federal income tax.

"Our long term growth strategy requires a fundamental reform of our tax code," Perry said in a speech in Las Vegas.

Perry's announcement to a group of Western Republicans gathered in Vegas came a day after Republicans had ganged up on Cain's 9-9-9 plan, which embraces major tax reforms - though the details have aroused strong GOP opposition.

Cain's plan sets a 9% rate on corporate income taxes, a 9% rate on personal income and a new 9% federal sales tax - that last item, which would be new - has sparked much of the opposition from fellow Republicans.

"Herman, I love you brother, but you don't have to have a big analysis to figure this thing out," Perry told Cain during Tuesday night's debate, as he knocked the idea of establishing a new federal sales tax and previewed his own tax reform idea which he says voters will embrace.

"They're not interested in 9-9-9, what they're interested in is flatter and fairer," said Perry.

"We'll see who has the best idea of how you get this country working again," Perry added.

The flat tax is nothing new - it's been floated in the Congress many times over the years, by members of both parties - but it's never really gone anywhere.

In fact, like most plans for major tax reform, I'm hard pressed to even remember a vote in the full House or Senate where lawmakers actually went on the record about a flat tax. The idea has simply never reached critical mass for a number of reasons.

Like the FairTax and Cain's 9-9-9 plan, the flat tax has its share of staunch critics, many of whom argue it would be wrong to do away with popular deductions like those for mortgage interest and charitable giving.

But maybe more importantly, Perry's signal that he's ready to back a flat tax could indicate that there is a growing desire for major change in the tax system - a system that has not been reformed since 1986, when Ronald Reagan was President.

Tax reform has been an issue just sitting on the sidelines for years. President George W. Bush had a commission on tax reform, but that report ended up in recycling bins all around Washington, D.C.

The Obama Administration has also talked about tax reform, but more in the context of finding ways to raise new revenue, something that Republicans oppose.

The flat tax got a lot of play back in the 1980's and 1990's, when it was championed by former Rep. Dick Armey (R-TX), but the bid went nowhere, opposed by interests in both the Democratic and Republican parties.

Now though, the calls of Tea Party Republicans and others for dramatic change in the makeup of the federal government could well aid those who want to do away with the Internal Revenue Service - or at least make major changes in the IRS.