https://en.wikipedia.org/wiki/Defection
In politics, a defector is a person who gives up allegiance to one state in exchange for allegiance to another, changing sides in a way which is considered illegitimate by the first state. More broadly, it involves abandoning a person, cause, or doctrine to which one is bound by some tie, as of allegiance or duty. This term is also applied, often pejoratively, to anyone who switches …