Susie Garza has never heard of Yang. But since February, she's been getting $500 a month from a nonprofit in Stockton as part of an experiment that offers something unusual in presidential politics: a trial run of a campaign promise, highlighting the benefits and challenges in real time.

Garza can spend the money however she wants. She uses $150 of it to pay for her cellphone and another $100 or so to pay off her dog's veterinarian bills. She spends the rest on her two grandsons now that she can afford to buy them birthday presents online and let them get the big bag of chips at the 7-Eleven.