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With his pick of Assistant EPA Administrator Gina McCarthy to head the agency, President Obama has signaled fidelity to his inaugural address promise to "respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations."

By that measure, there may be no candidate for EPA administrator better qualified to pursue that agenda than McCarthy.

As she heads toward her confirmation process, she's already facing a mixed response. Republicans specifically criticize her for crafting strict coal regulations, but even her critics find her personally approachable.

"You really can't expect him to hire someone like me for that job," frequent EPA critic and global warming skeptic Sen. James Inhofe, R-Okla, said. "She is of course nominated again and was appointed previously by Barack Obama, whose had about a 10-year battle on trying to kill fossil fuels. He's against oil, he's against gas, he's against coal, against all fossil fuels."

McCarthy is the architect of new CAFE, or corporate average fuel economy, standards that will require 39 miles per gallon for cars by the year 2016. She also crafted clean air regulations that virtually ended the building of new U.S. coal-fired plants.

Yet even many of those who oppose her agenda describe the Boston-born McCarthy as honest.

Inhofe recalls her response to his pointed question years ago, when he chaired the Senate Environment and Public Works Committee. He asked whether costly EPA air quality regulations would actually have any effect on reducing carbon dioxide levels worldwide.

"She said, no, it wouldn't because this isn't where the problem is. It's in China, it's in India," Inhofe said. "Well, that took a lot of courage to be that honest."

Elgie Holstein, senior director for strategic planning at the Environmental Defense Fund, said, "Gina McCarthy has a very well established reputation for working closely with people on both sides of the aisle. She's worked with several Republican governors including Mitt Romney when he was Governor of Massachusetts."

Still, her confirmation fight could be bruising. With the EPA set to release a series of new air quality regulations in the coming months, Sen. David Vitter, R-La., the ranking Republican on the Environment and Public Works Committee, and Rep. Lamar Smith, R-Texas, the chairman of the House Science, Space and Technology Committee, wrote McCarthy this week complaining of her failure to respond to repeated requests to provide the scientific data upon which the agency's mortality studies are based.

"Administration officials have repeatedly backtracked and reneged on promises to members of Congress to make the scientific information that underpins the agency's basic associations between air quality and mortality available," they wrote.

Chris Horner of the Competitive Enterprise Institute was behind the Freedom of Information Act request that led to a court-ordered release of thousands of alias emails used by former EPA Administrator Lisa Jackson. He now tells Fox News he's troubled by what those emails reveal.

"The dog not barking here is that emails from Gina McCarthy are very, very few and far between," Horner says. "(Jackson's) most frequent correspondence should have been Gina McCarthy and the records they're clearly withholding are the records from Gina McCarthy."

Another batch of alias emails from Jackson and other EPA officials is set to be released on March 15, with another batch to be released April 15.

McCarthy's confirmation is expected within the next few weeks.