After months of lockdown in which outbreaks of the coronavirus often centered in nursing homes, prisons and meatpacking plants, the nation is entering a new and uncertain phase of the pandemic. New Covid-19 clusters have been found in a Pentecostal church in Oregon, a strip club in Wisconsin and in every imaginable place in between. In Baton Rouge, La., at least 100 people tested positive for the virus after visiting bars in the Tigerland nightlife district, popular among Louisiana State University students. At a Christian summer camp near Colorado Springs, at least 11 employees fell ill just before the season’s opening, leading the camp to cancel overnight stays for the first time in 63 years. And in Las Vegas, just weeks after casinos reopened, a handful of employees from casinos, restaurants and hotels have tested positive, and frightened workers on Monday begged guests to wear masks in a news conference conducted over video.