If approved, does my travel authorization guarantee me admission to the United States?

If your electronic travel authorization is approved, this approval establishes that you are eligible to travel to the United States under the Visa Waiver Program, but does not guarantee that you are admissible to the United States. Upon arrival in the U.S. you will be inspected by a Customs and Border Protection officer at a port of entry who may determine that you are inadmissible under the Visa Waiver Program or for any reason under United States law.