By Phil KerpenPolicy Director, Americans for Prosperity

Today, on April 17, MoveOn.org sent out an urgent fundraising alert to try to save President Obama's faltering cap-and-trade energy tax, which as I've explained here in the FOX Forum would be the largest tax hike in history, and the White House has admitted it could be a tax hikes two-to-three times their official estimate.

Amazingly, MoveOn.org's Adam Ruben says in the e-mail:

"If Republicans convince voters that clean energy legislation amounts to a new tax, Obama's plan is toast."

Good news. It's a tax, and it's toast.

Cap-and-trade is a tax on coal, oil, and natural gas but instead of being a specific tax rate, the total level of use is capped and companies are forced to pay the government for emissions permits. They bid against each other to stay in business, and nobody knows how much the tax will be until they hold the auctions. It's a crazy, unpredictable tax, but it's certainly a tax.

White House Budget Director Peter Orszag admittedthat decreasing carbon emissions imposes costs and "much of those costs will be passed along to consumers in the form of higher prices for energy and energy-intensive goods."

In other words, it's a tax.

MoveOn.org's Ruben says:

"Republicans are telling a big lie to kill it. Their strategy is to frame the plan as a huge new tax on working families."

Does that mean White House Budget Director Peter Orszag is a Republican?

What about President Obama himself? He has a pretty clear understanding of how his plan works, which is to impose a huge tax on fossil fuels, making them so expensive that people won't be able to afford to use them.

Watch President Obama's own words on YouTubeif you have any doubt:

"Under my plan of a cap and trade system, electricity rates would necessarily skyrocket... whatever the industry was, uh, they would have to retrofit their operations. That will cost money. They will pass that money on to consumers."

In other words, it's a tax.

So you can listen to the president himself, his budget director, and every reasonable person who understands what a cap-and-trade system is designed to do -- tax energy -- or you can believe MoveOn.org and all the TV ads they're about to start running. Before you take their word though, keep in mind that these are same folks who told me last year that they would like to see gasoline prices go to 30 dollars a gallon.

The simple truth is that cap-and-trade is a tax. And on one thing I agree with MoveOn.org: as long as people understand it's a tax, it's toast.

Mr. Kerpen is director of policy for Americans for Prosperity.

Phil Kerpen is the founder of American Commitment Action Fund, on the web at www.BookerFAIL.com.