WASHINGTON — Few lobbyists have walked into the kind of political inferno that greeted Stephen J. Ubl when he became the top pitchman for the pharmaceutical industry.

Mr. Ubl, the 47-year-old president and chief executive of the Pharmaceutical Research and Manufacturers of America, took charge in November, as the Obama administration, presidential candidates, members of Congress, consumer groups, health insurance companies and doctors were criticizing the prescription drug industry for charging prices they saw as exorbitant and excessive.

The anger has only grown worse.

“Enough is enough,” Senator Bernie Sanders of Vermont, the firebrand Democratic presidential candidate, wrote on Twitter on Thursday. “Pfizer and other pharmaceutical companies can no longer be allowed to rip off American patients.”

That anger is just one of the challenges facing Mr. Ubl.

“The debate around drug pricing is myopic and misinformed,” he said in an interview. “It’s myopic because 80 percent of health care costs or more are driven by a small percentage of patients with multiple chronic conditions.”