Republicans want to make sure that the EPA doesn't use the Clean Air Act to do by regulation what Congress refused to do in legislation: pass a cap and trade law aimed to reduce carbon emissions by taxing them:

"Now we face the threat of the EPA bureaucrats imposing the same agenda through a series of regulations," says Rep. Fred Upton (R-Mich.). "Like cap and trade, these regulations would boost the cost of energy not just for homeowners and car owners but for businesses large and small."

And Sen. James Inhofe (R-Okla.), who testified before the House committee, argued that using regulations to limit emissions would hit taxpayers hard.

"All these bills," he said, "along with the Kyoto Treaty would cost in that range of somewhere between 300 and 400 billion dollars a year."

But Democrats questioned the entire purpose of the hearing. "Today we hold a hearing on legislation," said Rep. Henry Waxman (D-Calif.), "that would roll back the Clean Air Act and block the EPA from regulating dangerous carbon emissions from power plants, oil refineries, and other large polluters."

And Rep. Edward Markey (D-Mass.), another supporter of cap and trade, said a law Republicans are proposing "ties EPA's hands and prevents it from moving forward with any regulations to reduce global warming pollution."

Democrats accused Republicans of trying to weaken the Clean Air Act and endanger health, but Republicans struck back, noting none of the six pollutants covered by the Clean Air Act would even be affected.

They include lead, sulfur dioxide, carbon monoxide and others...but not carbon dioxide, the greenhouse gas EPA wants to regulate:

Nebraska Republican Congressman Lee Terry told EPA Administrator Lisa Jackson that "the Clean Air Act does not give you that authority."

"The United States Supreme Court says it does," she replied.

And Rep. Waxman added, "The reason this is under the Clean Air Act is because the Supreme Court, by 5 to 4, said EPA must regulate if they have an endangerment finding."

But Republican Joe Barton of Texas told Administrator Jackson that this is not the case.

"Madam Administrator," he said, "CO2 is not mentioned in the Clean Air Act. It's a 5 to 4 decision that it might be. It's your administration's position that it should be... But that doesn't mean that it has to be" (italics added).

Republicans fear the EPA is about to unleash a torrent of regulations:

Republican Ed Whitfield of Kentucky says, "The Obama Administration has been the most aggressive in recent memory. As a matter of fact, six rules were issued on Christmas Eve. And there's a pipeline full of regulations waiting to be issued."

...Which Democrats, including Rep. Jay Inslee of Washington, don't want to stop. "When you gut the EPA's ability to enforce the law, you turn the Environmental Protection Agency, into the Environmental Pathetic Agency. That is not what Americans want."

Jim Angle currently serves as chief national correspondent for Fox News Channel (FNC). He joined FNC in 1996 as a senior White House correspondent.