Gina McCarthy could get blame for job-crippling environmental rules or credit for cracking down on carbon emissions -- or both

You could argue that the most powerful member of President Obama's second-term Cabinet isn't even on the job yet.

"I didn't go to Washington to sit around and wait for congressional action; never done that before and don't plan to in the future."

Gina McCarthy, Obama's climate warrior and pick to lead the Environmental Protection Agency, is stuck in confirmation limbo. It's hardly surprising, considering that she has become a lightning rod in the battle over the environment as Obama works to enact unprecedented U.S. regulations on power plants.

Rebuffed by a Congress with little incentive to budge on climate change, Obama has decided to go it alone on fighting warming temperatures. Rather than presenting lawmakers with a legislative plan to cap carbon emissions, Obama is turning to his EPA to implement the most extensive environmental regulations in decades.

And now, McCarthy, a top official in former Republican Massachusetts Gov. Mitt Romney's administration, could become the poster child for job-crippling environmental standards or be credited with starting the federal government's largest crackdown on carbon emissions -- or both.

"I didn't go to Washington to sit around and wait for congressional action; never done that before and don't plan to in the future," McCarthy, the EPA's air division chief said, giving the keynote speech at an environmental education event in 2010 at her alma mater, the University of Massachusetts in Boston.

Three years later, on the verge of assuming the nation's top environmental post, that is exactly what she is doing. But it likely won't last for long. If and when McCarthy is confirmed -- Senate Majority Leader Harry Reid says he will bring her nomination to the floor after the upper chamber has pushed through immigration reform -- the 58-year-old with a heavy South Boston accent will become the public face of Obama's State of the Union pledge to curtail the "global threat of our time."

Frustrated by Obama's reluctance to stop the Keystone XL Pipeline, which would carry oil from Canada to Gulf Coast refineries, environmental groups see in McCarthy somebody who can put the president's environmental agenda into high gear.

"If there are to be any initiatives that will reduce emissions from power plants, it's going to be up to the EPA and Gina McCarthy -- that's a Herculean task considering the political winds surrounding this issue," said Frank O'Donnell, president of the nonpartisan Clean Air Watch.

At the core of Obama's environmental push are tighter rules for power plants, more energy-efficient buildings and appliances, and additional green energy development on public lands. For environmentalists, stricter restrictions on current coal-burning power plants have long been viewed as the crown jewel of their agenda, but it's also an objective likely to prompt a flurry of lawsuits and stoke GOP charges of presidential overreach.

McCarthy helped craft tougher rules for new power plants but the EPA has yet to put the directive into effect, much to the chagrin of the environmental lobby.

The EPA blitz will take place as the administration attempts to implement another overhaul with even more bureaucratic challenges: Obamacare.

"It's almost too good to be true," said one high-ranking Republican Senate aide. "It's one train wreck on top of another train wreck. We just have to stand back and watch the carnage."

McCarthy has spent three decades crafting environmental regulations at the federal and state levels, including Massachusetts's first climate-protection action plan; experience that is expected to help her as she blalances federal, state and local interests -- against a backdrop of court challenges. Before landing at the EPA, she was commissioner of the Connecticut Department of Environmental Protection, also in a Republican administration.

As her confirmation battle heats up, White House officials are expected to focus extensively on McCarthy's bipartisan background. And she has won at least begrudging approval from those whom she wants to regulate further.

"I think that she is at least a nominee that is willing to sit down and talk to the regulated community," said industry lobbyist Scott Segal, a partner at Bracewell & Giuliani. "In that respect, she's an improvement [over her predecessor]. However, the rules she has generated [in the EPA's air division] are some of the most expensive in the history of the agency -- and that's sobering."

In addition to laying the framework for myriad regulations, McCarthy's short-term goal is to convince industry advocates her agenda won't carry unintended consequences. For example, Segal argued that McCarthy's marching orders, particularly the stricter rules for coal-burning plants, would force businesses to relocate to countries with looser laws, essentially outsourcing American jobs.

She is unlikely to appease Republicans, who say the EPA hasn't been responsive to Freedom of Information requests and has used personal email accounts to avoid congressional oversight.

The inevitable collision course between McCarthy and GOP lawmakers, however, is fueled mostly by opposing ideologies and the belief that this explosive debate will have ramifications well after Obama leaves the White House.

"We don't have a problem with her personally," a GOP leadership official on Capitol Hill said. "She's actually kind of endearing. But unfortunately, our views are just too far apart. So yeah, you could view this as the opening act of many battles to come."