No, the store owner is completely wrong about being able to refuse service to anyone. Under the Civil Rights Act of 1964 and the Americans With Disabilities Act, a business that engages in commerce and offers a place of public accommodation (read "store") must be non-discriminatory. The famous Heart of Atlanta Motel case (see http://www.oyez.org/cases/1960-1969/1964/1964_515) is the "case on point." There are protected classes of people and a person with disabilities -- even with a guide dog -- is a protected person under Federal and state law. The store owner's ignorance of the law is no excuse and no defense.
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