When a U.S. president nominates a candidate to take over the top spot at a major government agency such as the Defense Department, at least a few senators—usually from the opposing party—raise some objections, if for no other reason than to show that they will not rubber-stamp anyone the president proposes.

But yesterday Republicans boycotted a vote on Gina McCarthy, President Barack Obama’s nominee to become the new administrator of the Environmental Protection Agency. She would fill the spot left by Lisa Jackson, who stepped down. McCarthy faced little dissent when the Senate Environment and Public Works Committee held confirmation hearings in April. But just before the committee’s scheduled vote on her nomination yesterday, which would have sent her name to the full Senate for a final confirmation, all eight Republicans on the committee of 18 failed to show up. Under Senate rules, the vote could not be taken.

The move was a surprise to committee chairwoman Barbara Boxer, a Democrat. In a last-minute letter sent to her by the Republican members, they said they wanted more answers about former administrator Jackson’s occasional use of a personal email account to conduct EPA business, allegedly to cloud transparency. After many Democrats objected loudly to the boycott—a rare event, reserved for a very contentious nominee—the Republican committee members indicated indirectly that they were not against McCarthy per se, but that their questions to her, during the hearings, about email conduct were not answered adequately. Critics of the move called it a stunt, pointing out that David Vitter, the top Republican on the committee, had asked McCarthy a record-breaking 653 questions, which she had answered.

Although neither the committee nor Boxer has released a statement yet about what might happen next, Congress-watchers say a new vote would be unlikely for two to three weeks.

More objections could arise if McCarthy’s name goes to the full Senate. Minority Leader Mitch McConnell, for one, has said that he opposes the nomination because McCarthy would thwart the coal industry in his state of Kentucky. “I am concerned,” he wrote in a statement issued by his office, “that Gina McCarthy would continue to foster this administration’s radical environmental and anti-coal jobs agenda.”

The sudden blockade is surprising and disappointing because McCarthy has succeeded in bridging the infuriating gap between parties. McCarthy, 58, has been director of the EPA’s Office of Air and Radiation for four years, where she has developed a reputation for taking a collaborative, common sense approach to devising regulations. A shining example was her central role in setting new carbon pollution standards, issued jointly in 2011 with the Transportation Department’s new Corporate Average Fuel Economy (CAFÉ) standards, which raised the gas mileage that new cars and trucks must get by as a much as 50 percent by 2025. Although the rules are challenging, automobile manufacturers as well as consumer and business groups ultimately embraced them. The regulations, McCarthy told the Senate committee during the hearings, would save Americans more than $1.7 trillion in fuel costs and eliminate six billion tons of carbon pollution.

Her efforts earned praise from Richard Eidlin, policy director for the American Sustainable Business Council. In a May 1 blog for The Hill, a Web site that watches Congress, he wrote: “It is one of the great myths of our political debate that we must choose between economic growth and environmental protection. Gina McCarthy…has spent her career proving this a false choice.” He added that McCarthy has a knack for devising solutions to environmental issues that can improve market certainties and thus create opportunities for businesses.

Part of McCarthy’s ability to reach compromise stems from her prior posts. The Boston native was an environmental advisor to five Massachusetts governors—Democrats and Republicans—including former Gov. Mitt Romney, and was commissioner of the Connecticut Department of Environmental Protection.

If approved, McCarthy could face issues that have been simmering at EPA because they are thornier than CAFÉ standards. Of note are proposed regulations on power plant emissions, a decision for President Obama on whether to approve the Keystone XL pipeline to bring tar sands oil from Canada to the U.S. (which would raise carbon dioxide emissions in North America), and the never-ending battle between environmental and business groups over enforcement of clean air and water laws. Also, EPA’s multi-year study on the controversial environmental impacts of natural gas fracking is due in 2014.

Image courtesy of EPA on Wikimedia Commons