Just as an FYI, some paraphrased (from my Webster’s dictionary)
refugee: someone forced to move to another country to escape danger or persecution
émigré: emigrant, especially one forced to emigrate for political reasons
emigrant: one who emigrates, [leaves one's place of abode or country for life or residence elsewhere]
immigrant: a person who comes to a country to take up permanent residence
(The dictionary lists emigrant and immigrant as synonyms.)
Migrants move regularly, to find work, e.g. crop harvesting
Wikipedia mentions that émigré got its political connotations from people who fled the French and Russian revolutions; it also says the term is more politically charged than “exile,” which describes people who were forced out of their native countries.