The shadow of C. Everett Koop looms large at the Children's Hospital of Philadelphia. Much has changed since he started here in 1946, but his fundamental discoveries in our discipline inform our work daily. And Koop was not reticent. Moved that even the littlest newborns with severe congenital defects could be saved by modern surgical techniques, the evangelical Christian Dr. Koop wrote and spoke forcefully against abortion.

When Koop was nominated for surgeon general, those views tormented his months-long confirmation process in 1981. If those hearings had gone another way, Americans would have been deprived of perhaps the most successful, high-profile public health interlocutor of our times. Koop would turn the tide against tobacco-related illness and make America conversant about the AIDS epidemic.

Thirty-three years later, Dr. Vivek Murthy, President Obama's nominee for surgeon general, sits in another confirmation limbo, hobbled not by abortion, but over disagreements on health care and guns. And time is running out. If the nomination does not come up for a vote in this lame-duck session, it is unlikely to go anywhere in a GOP-majority Senate in January.

Murthy founded an advocacy organization, Doctors for America, that supported the Affordable Care Act as a good beginning to health-care reform. That support is polarizing enough in today's political climate, but despite Murthy's insistence that his focus as surgeon general would be on obesity, mental health, and vaccine-preventable illness, what really threatens his nomination is the National Rifle Association.

The NRA is vilifying Murthy for Doctors for America's position on gun violence in the wake of Sandy Hook. The group called for reversing restrictions on gun-violence research and for limitations on access to assault rifles, positions completely consonant with the American Medical Association and dozens of law-enforcement, community, and health-care associations.

Yet consider what the well-respected Dr. Koop said about guns in a 1992 article:

"We propose that the right to own or operate a firearm carries with it the same prior conditions, namely, that the owner and operator of a firearm also meet specific criteria:

be of a certain age and physical/mental condition;

be required to demonstrate knowledge and skill in proper use of that firearm;

be monitored in the firearm's use; and

forfeit the right to own or operate the firearm if these conditions are abrogated.

"These restrictions should apply uniformly to all firearms and to all U.S. inhabitants across all states through a system of gun registration and licensing for gun owners and users."

Murthy is targeted as a radical for advocating firearm restrictions that are less stringent than what Koop called for then - what nearly every major physician group calls for today. It is ironic that a physician, Sen. Rand Paul (R., Ky.), placed a hold on Murthy's nomination, perhaps for political reasons of his own.

As to the criticism that Murthy is too young at 36 to be surgeon general, remember that the Senate had to change existing law to accommodate Koop. He was too old for the post when he took office in 1981.

The Senate displayed forbearance in granting Koop a chance to serve despite his unapologetic condemnation of abortion, and Koop reciprocated by serving with historic distinction. Murthy has made it clear that he, too, has no interest in donning the surgeon general's uniform to vitiate a polarized American debate. His focus on mental-health issues and qualifications to lead on Ebola - he has deep experience in infectious disease - make his confirmation an urgent necessity.

Will the Senate face down the NRA and give Murthy the same opportunity it offered Koop? What an enormous tragedy it would be if lawmakers fail this important test.

Aseem R. Shukla is a pediatric urologist at the Children's Hospital of Philadelphia. The views expressed are the writer's.