It can seem to public health officials that giving an inch means people will take a mile. In the months since most U.S. states emerged from coronavirus lockdowns, wearing a mask has become a matter of politics more than safety, “pandemic parties” have been broken up in California, New York and Florida, and many states that forged ahead with reopening plans in May have been forced to pause or reverse the orders. It’s in this fraught climate that public health experts are saying that if other less-extreme measures are not working or being ignored, another round of lockdowns — as politically unpopular as they may be — may be the only way to keep an already-dire situation from spiraling further out of control.