Ports of entry to the US are staffed by authorities who have the discretion to deny entry into the country. You can be denied entry into the US even if you have a visa and authorization to enter the US as well as an airline ticket into the US. There are many reasons to be denied entry into the US. If you have been denied entry before, this can be considered due cause to be denied entry again. As well, if border authorities believe that you pose a threat in any way, are engaged in criminal activity or have a criminal record, these can all be grounds for denying you enter into the US.
If you are being denied entry into the US, the most important thing to do is to remain calm. Arguing will not help and will usually hurt your case. If you can, consider returning home and consulting with a US immigration attorney to ensure that you can re-enter the US again. Contact your airline to see if you can get a refund of your ticket.
The best way to deal with being denied entry is to prevent it from taking place in the first place. The best way to do this is to ensure that you arrange for proper authorization to enter the US well ahead of time. If there is anything in your past that could cause you to be denied entry into the US – such as a criminal record or a previous denial of entry – speak with a good US immigration attorney before you travel and before you make your travel plans. An experienced attorney can advise you on the best ways to avoid this problem. When traveling to the US, make sure that you bring all your relevant documentation, ID, and any information about what you will be doing in the US. You will also want to buy travel insurance that will refund your money in case you miss your flight and in case you are denied entry. As well, always travel with extra money in case you do need to find your way home after being denied entry. The truth is, no one is guaranteed entry into the US. Even if you have all your visas, authorizations, and paperwork, you may still be denied entry.