CVS-Aetna, Walgreens, Walmart, Amazon, Optum-United Health Group — they’re all buying primary care practices or hiring primary care practitioners (PCPs) directly. Never before have the titans of capitalism shown such interest in the humble family physician. And therein lies a story with huge but uncertain implications for American health care. This new trend could greatly bolster, or dangerously distort, U.S. primary care, a critical component of a healthy health care system.