Ever since Colin Powell endorsed Barack Obama for President in both 2008 and 2012, it has been clear that his claims to be a Republican were nonsense. Now he is on record endorsing single-payer health care for the U.S., see a U.S. News & World Report article for details.
Powell endorses Democrats, speaks out in favor of socialized health care, and claims to be a Republican. Powell fails the "duck" test: if a creature waddles, swims and quacks, it's a duck; regardless of what it may claim.