America's population is older than it's ever been, according to U.S. Census Bureau data. About 18 percent of Americans are at least 65 years old, a number that's projected to hit 28 percent in 30 years. And as that demographic grows, some of them are reimagining retirement. Ali Rogin reports for our series, "Rethinking Aging." PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders