But Robert Shireman, a former Education Department official who helped shape that original plan, said the intense politics surrounding the issue played a part in “watering down” the final result.

“From early on, the industry was going to friends inside and out of the administration and saying, ‘They’re out to get us,’ and creating the impression that these regulations were unfair or irrational,” said Mr. Shireman, who left the department before the plan was finished.

“They decided to raise holy hell,” he said in an interview.

Many colleges saw the federal government’s attacks as “Armageddon for the industry,” said Avy Stein, a partner at a private equity fund that owns a network of schools called Education Corporation of America.

The industry was on the defensive after a series of federal investigations portrayed it as rife with abuse. They found that recruiters would lure students — often members of minorities, veterans, the homeless and low-income people — with promises of quick degrees and post-graduation jobs but often leave them poorly prepared and burdened with staggering federal loans.

In response to the rising concerns, 18 months ago the Obama administration proposed its tough restrictions linking tens of billions of dollars in federal student aid to formulas measuring students’ debt levels and income after graduation. Colleges whose students were not earning enough money to start paying back their loans would be in danger of losing federal aid altogether.

The proposal was aimed at ensuring that the for-profit schools were providing “gainful employment” in a wide range of vocational fields they taught, like medical testing, massage therapy, business management and cosmetology. The joke in Washington, however, was that the industry effort to defeat the plan mainly ensured “gainful employment” for the capital’s Democratic lobbyists and political consultants.

In a coordinated approach that also included Capitol Hill protests, petition drives, newspaper ads and more, industry advocates stressed that jobs that would be lost if the institutions were put out of business. They questioned why nonprofit schools were untouched. And they accused the administration of highlighting some abuses to stigmatize an industry that educates second-chance students shunned by traditional academia.