How the immigration debate pits national security against family unity

SALT LAKE CITY — The standoff in Washington over immigration policy and whether it should be possible to bring family members to America — a process called "family reunification" by those who support it and "chain migration" by those who oppose it — feels very personal to Jean Claude Iyanuremye.
Iyanuremye lived in America three years before his family was allowed to join him. The Congolese man, now 30, arrived as a refugee in 2014 and tried to build a new life, but his thought