New York Gov. Andrew Cuomo and New Jersey Gov. Chris Christie continued to defend a newly instituted mandatory Ebola quarantine policy for New York and New Jersey airports amid criticism from the White House. The political battle unfolded as Dr. Craig Spencer, the first confirmed Ebola patient in New York City, was responding well to treatment at Bellevue Hospital in Manhattan.

Spencer has experienced gastrointestinal symptoms associated with Ebola and is listed in serious, but stable, condition. "The patient looks better than he looked yesterday. ... He tolerated the plasma treatment well and had a good night sleep. From his first day here, he expressed gratitude with the care he is receiving under the watchful eye of the dedicated, well-trained and professional team of ICU physicians and nurses who are exclusively assigned to his care," Ram Raju, New York City Health and Hospitals Corporation president, said in a statement Sunday. Nancy Writebol, a nurse who survived Ebola, gave blood, which will be used in Spencer's treatment.

New York, New Jersey and Illinois introduced Friday a mandatory quarantine for any traveler who has had direct contact with an Ebola patient. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said the quarantines could have "unintended consequences of disincentivizing health care workers" from volunteering in West Africa. President Barack Obama urged the public and any response to be "guided by science" during his weekly address Saturday.

Amid the growing criticism, Cuomo and Christie softened their policy by allowing for home quarantine. "My practice has always been to err on the side of caution, hope for best, prepare for worst," Cuomo said during a press conference Sunday. Cuomo and Christie actively defended the policy on Twitter and during press stops.

While Cuomo and Christie adopted the policy after the first confirmed Ebola case in New York City, Illinois Gov. Pat Quinn, who is facing tough fight for re-election next week, has instituted a similar policy.

"This protective measure is too important to be voluntary. We must take every step necessary to ensure the people of Illinois are protected from potential exposure to the Ebola virus. While we have no confirmed cases of the Ebola virus in Illinois, we will continue to take every safeguard necessary to protect first responders, health care workers and the people of Illinois," Quinn said in a statement.

Chicago's O'Hare International Airport is one of five U.S. airports that require enhanced screening procedures for travelers coming from West Africa.