Critics of the bans point to Jeff Zients, the coordinator of the White House’s coronavirus pandemic response, as the main obstacle standing in the way of easing the longstanding restrictions, according to five people familiar with the matter. And some of them have grown so frustrated with Zients that they said they have begun discussing ways to go around him and take their case to other top administration officials instead... “I think the American people are owed an explanation: What the hell happened?” said Rep. Brian Higgins (D-N.Y.), one of 75 lawmakers who sent a letter to Biden last week urging him “to begin taking science-based, data-driven steps to safely reopen international travel to the United States.” Sens. Jacky Rosen (D-Nev.) and Rick Scott (R-Fla.) are preparing to send a letter to Biden as well, according to a Senate Democratic aide. Some senior officials in the Biden administration, including Cabinet secretaries and doctors, have expressed support for easing the restrictions as long as travelers coming into the U.S. can prove they have received vaccinations or provide a negative Covid test. But the administration remains resistant to asking businesses, including airlines, to require proof of vaccination, according to two senior administration officials familiar with the deliberations.