In expedited removal, you will never even get out of the airport before you are sent home, and you will not receive a hearing before an immigration judge. The justification for this practice is that you have not formally entered the US (you have not yet passed through immigration inspection).
At the border, you do not have the same rights as people who formally entered the US as a result of passing through immigration inspection (by, for example, presenting a passport to an immigration officer and being waved through). Expedited removal might occur if, for example, you present a fake passport to the immigration examiner, or fly to the US without a valid visa. The number of expedited removals has increased drastically over the past few years.