The motivation would be to remove Erdogan who is moving towards a "less democratic Turkey" and replacing him with a president that is more friendly to the US.

The motivation would be to remove Erdogan who is moving towards a "less democratic Turkey" and replacing him with a president that is more friendly to the US. Influencing the following election would probably happen as well. A new president could help isolate Russia, provide more advantageous basing agreements for the military, and in general do what the US government wants.