Sales tax is not regressive per se. It's just much less progressive than an income tax. Rich people still pay more overall since they spend more money.
An example of a regressive tax would be something like cigarette taxes - poor people would actually spend a larger share of their income since they are also more likely to smoke.
An example of a regressive tax would be something like cigarette taxes - poor people would actually spend a larger share of their income since they are also more likely to smoke.