Gov. Rick Perry has built a political career running against Washington, and no agency more symbolizes what he considers the meddlesome and economy-choking evils of the federal government than the Environmental Protection Agency.

Perry’s conservative views on business costs, states’ rights, job creation, energy policy and global competitiveness — the core of his governing philosophy — are illuminated most vividly in his clashes with the EPA over issues like pesticide regulation and global warming.

From his earliest days as head of the Texas Department of Agriculture to his current campaign for the Republican presidential nomination, he has struck a consistent anti-regulatory chord.

He brags that he has significantly reduced air pollution over his decade-plus tenure by working with businesses and does not need new overbearing mandates from environmental nannies in Washington.

But EPA officials and more independent analysts outside government said that Perry was claiming credit for improvements in air quality brought in large measure by the very federal laws he has resisted and railed against, and that air pollution in Texas remains worse than in nearly every other state.

“His constituents are benefitting from the Clean Air Act that the EPA is enforcing,” said Janice E. Nolen, assistant vice president for national policy at the American Lung Association. “It’s happening in Texas, but not only in Texas, which tells us that it’s federal action that is responsible.”

David E. Adelman, professor of environmental law at the University of Texas Law School, said the state had made progress in reducing pollution, but still had a long way to go. “For the most part, Texas has lowered its toxic emissions, but so has essentially every other state in the country,” he said, referring to airborne toxins like benzene and butadiene. “The key point to recognize is that Texas started so much higher than everyone else.”

Catherine Frazier, a Perry campaign spokeswoman, said in an e-mailed statement, “If elected president, the governor’s energy priorities will be centered around scaling back the EPA’s intrusive, misguided and job-killing policies, which will empower states to foster their own energy resources without crippling mandates and open the doors for our nation to pursue and strengthen an all-of-the-above energy approach.”

Frazier said that Texas had achieved large reductions in pollution by following its own path and asserted that some federal actions were driven by politics rather than science.

Perry used more colorful language this month in addressing a Tea Party group in Florida.

“Somebody has to tell the EPA that we don’t need you monkeying around and fiddling around and getting in our business with every kind of regulation you can dream up,” he said. “You’re doing nothing more than killing jobs. It’s a cemetery for jobs at the EPA”

The main environmental battles of his governorship have centered on air pollution. Texas, with its large presence of oil refineries, chemical plants, cement kilns and other dirty industries, has struggled with emissions of both toxic pollutants and smog-forming compounds. Perry has repeatedly challenged federal regulators, in court and in public statements, over enforcement of the Clean Air Act, arguing that the state’s unique, flexible, business-friendly approach is more effective than the federal strategy for controlling air quality.

Texas is also the largest emitter of carbon dioxide and other greenhouse gases in the country — and the only state that has refused to abide by nascent federal greenhouse gas regulations. As a result, the EPA seized control of greenhouse gas permits issued in the state early this year.

Republican politicians in Texas have long thrived on lashing out against federal regulation, but critics say Perry has taken it to new levels, picking fights with the EPA even when it is not in the state’s interest.

EPA officials declined to comment on the record about their relations with Perry, saying they did not want to insert themselves into the presidential campaign. But they say they have worked cooperatively with lower-level Texas officials, who often seek federal technical guidance and money to address environmental problems. Recently, for example, the EPA paid for and installed air-quality monitors near several natural gas wells at the request of Texas officials.

The fights have been so bitter and the progress so hard-won in the Perry years that some environmentalists practically wax nostalgic for Perry’s predecessor, George W. Bush, who as governor signed a bill intended to clean up old coal plants and put Texas on course to becoming the leading wind-power state.

“Bush was far better as governor in terms of his environmental interests,” said Tom "Smitty" Smith, the director of the Texas office of the advocacy group Public Citizen.

No one disputes that during Perry’s tenure, the state’s air has become much cleaner. Ozone emissions fell by 27 percent from 2000 to 2009 — a greater drop than in any other state, according to the Texas Commission on Environmental Quality, the state’s environmental monitor. Air emissions of toxic chemicals fell 41 percent over the same period, the agency said.

Houston, which had the worst smog problem in the nation during Bush’s last years as governor, has substantially cleaned up its air: in 2007 it had just 38 bad ozone days, compared with 100 for Los Angeles. Houston remains out of federal compliance with federal ozone regulations, however, as does Dallas-Fort Worth, and this year the numbers in some cities are expected to be worse than last’s years as a result of the extreme heat that much of Texas suffered all summer.

Perry takes credit for the improvements, attributing them to state programs like flexible permitting, a system in which pollution output is capped according to a plant’s entire output rather than smokestack by smokestack. Air quality progress, the governor has said, has come despite what he consistently derides as orders from Washington.

Perry assailed the clean air rule that a Texas power generation company blamed this month as the reason it will have to close power plant units and lay off 500 workers. “Yet again, this administration is ignoring Texas’ proven track record of cleaning our air while creating jobs, opting instead for more stifling red tape,” Perry said in a statement.

Tensions with the EPA have increased strikingly since the Obama administration appointed a new regional chief, Al Armendariz, an El Paso native. Armendariz, unlike many past regional EPA chiefs, has an engineering background and is a former professor at Southern Methodist University.

“This definitely has been the most confrontational that I’ve seen in the last couple of decades, almost to the point of being personal in terms of Perry lashing out at Armendariz,” said Ken Kramer, director of the Texas chapter of the Sierra Club.

Perry and Armendariz have clashed over flexible permitting, practiced by Texas since the early 1990s. The EPA argued that the permits allowed for too much overall pollution and were impossible to police. Texas has hit back against what Perry called an intrusive regulatory regime imposed by “environmental statists.”

Ultimately, Texas lost the battle, and most of the facilities are now making a transition to standard EPA rules.

Perry has reserved special wrath for the Obama administration’s intention to regulate climate-altering gases. Perry, who was a supporter of Al Gore’s 1988 presidential campaign, has denounced climate scientists as grant-seeking frauds and the effort to control greenhouse gases as a “contrived, phony mess.”

Texas led more than a dozen states in suing the EPA to halt its greenhouse gas regulation program and has refused to participate in the federal permitting system that every other state now follows. The case is pending.