"She has been pushing very hard internally to see that those words mean something," Blumenfeld says. Under her watch, the agency has begun to review whether the toxic exposure standard, which was based on a 158-pound adult, unfairly exposes women, Asians and Latinos (all of whom tend to be smaller) to more pollution. She is the first EPA administrator since 1976 to prioritize a review of the Toxic Substances Control Act, deputizing her staff to determine whether chemical manufacturers should have to prove their products' safety. (As it stands now, the public has to prove new chemicals cause harm.) And she has given regional administrators like Blumenfeld enormous autonomy to carry out her directive: to look in the poorest communities, tribal lands and Spanish-speaking enclaves for examples of public health injustice.

Blumenfeld responded to the Kettleman City crisis, he says, "because it's a textbook example of a community where the voices hadn't been heard, where they weren't getting timely and accurate data about their environment -- whether they should stay inside on a certain day because of the air, whether a sewage spill had happened in their neighborhood, what's in their water. And what they demanded was quite simple: Help us determine why we're having birth defects in our very small community."

It's also an example of politics so local they can't be partisan. "If you live next to a Superfund site, you want to clean it up," Blumenfeld says. "It doesn't matter what political stripe you are. On a national level, environmental issues have become unfortunately polarized. We need to bring environmental issues back to a place where people understand what the impact is on them and their families."

"Blumenfeld is the highest-ranking EPA official ever to visit Kettleman City," Angel says. "For the first time ever, under Democrats or Republicans, we seem to have an Environmental Protection Agency that wants to protect the environment."

The first two years of any presidency is seldom a time of great action and momentum. Bush's chief environmental achievement was probably the creation of several protected ocean areas, and he didn't designate his first one, a marine national monument around the Hawaiian Islands, until halfway through his second term. He was on his way out the door in 2009 when he created his last three sanctuaries, 200,000 square miles of protected waters around U.S.-controlled islands in the Marianas Trench.

Bill Clinton established his own environmental legacy in the same fashion. Although throughout his two terms his administration strengthened air quality standards and restored emphasis on public health at the EPA, the only major coup of his first two years was Sen. Dianne Feinstein's pet project, the 1994 California Desert Protection Act.

By that measure, Obama has been an activist. Interior has not yet succeeded in extracting details about the chemicals natural gas companies use in hydraulic fracturing, but over howls of protest from Rep. Doc Hastings, R-Wash., Salazar has considered restricting the practice on federal lands. Obama avoided the word "climate" in his Jan. 25 State of the Union speech, but his proposed shift toward 80 percent "clean energy" by 2035 acknowledged the threat. And while Obama includes nuclear in that mix, he has at least fulfilled his promise to halt the $14 billion boondoggle called Yucca Mountain, a proposed national nuclear waste facility in Nevada's earthquake country.

Most ambitious of all has been the EPA, whose staff has rolled out a series of updates to the Clean Air Act, including rules to reduce emissions of carbon dioxide and other greenhouse gases from new and retrofitted power plants and factories; limits on carbon dioxide emissions from passenger cars and the first-ever greenhouse gas standards for heavy-duty trucks. And for the first time in 40 years, the EPA has tightened the rules for measuring sulfur dioxide, most of which is emitted from coal plants.

In response, the troops are massing on Capitol Hill. U.S. Chamber of Commerce President Tom Donahue has called upon the new Republican House majority to halt the EPA's "regulatory tsunami," and his allies in the House have some bipartisan support in the Senate: Jay Rockefeller, D-W.Va., has put suspending EPA climate rules on his list of 2011 priorities. Rep. Fred Upton, R-Mich., expects Jackson to spend so much time defending her policies in Congress that he jokes about saving her a parking spot.

Obama may be trying to head them off. The late January departure of his climate czar, Carol Browner (who also ran Clinton's EPA), has been interpreted as a business-friendly adjustment. In a Jan. 18 executive order, Obama also called for a government-wide review of federal regulations to find out which ones pose "unreasonable burdens" on business. But whatever shifts and concessions the president makes, and however hard Congress presses to undo what's been done, it's hard to imagine very many lawmakers, however partisan, rising up to halt an investigation into what ails Kettleman City, or ripping out a solar farm responsibly sited and newly risen in the desert.

When I talked to Jeff Ruch again in early January, he struck a more measured tone than he had last fall. He praised Interior's new proposal to bring scientific integrity back to the agency as "a major improvement" and urged EPA and NOAA to do the same. PEER had just won a signal battle in getting a whistleblower from the U.S. Park Police restored to her job; the outrage that fueled his earlier conversations had diminished. But he remained frustrated with the administration's tendency to negotiate where he thinks it ought to fight. And he still wondered whether Obama had it in him to stand his ground in difficult negotiations over laws protecting endangered species and public health.

"He's got to keep his eye on whatever greater good he's trying to achieve," Ruch said. "Nature is not a chip to be bargained away."

This coverage is supported by contributors to the High Country News Enterprise Journalism Fund.

Judith Lewis Mernit has written about energy and the environment for the Los Angeles Times, Mother Jones, Sierra and Utne Reader. She is a High Country News contributing editor.