Jonathan Zimmerman teaches history at New York University and lives in Narberth. He is the author of "Small Wonder: The Little Red Schoolhouse in History and Memory" (Yale University Press). He can be reached at jlzimm@aol.com.

Advocates of the extraction process known as "fracking" say it's safe, yielding vast quantities of natural gas without polluting our land and water. So, they say, federal environmental regulators should back off.

And that, my friends, is what philosophers call a non sequitur. Let's hope it's a nonstarter, too.

Fracking, short for hydraulic fracturing, involves pumping chemical- and sand-laden water deep into the ground to break up rock formations and release gas. If it's as safe as its supporters say it is, they should welcome federal oversight. Their very resistance to scrutiny suggests it might not be so safe after all.

Consider the FRAC Act, cosponsored by Sen. Bob Casey (D., Pa.), which would allow the federal Environmental Protection Agency to regulate the chemicals gas drillers use. The bill has sparked outrage within the industry and the Republican Party, whose leaders seem to be trying to outdo each other in condemning the EPA.

Rep. Michele Bachmann, for example, has promised to padlock the EPA's doors if she's elected to the White House. Texas Gov. Rick Perry, the front-runner for the GOP nomination, pledges to impose a moratorium on all federal environmental regulation, saying it should be left to the states....