About 800,000 people in the United States, and 8,000 in Massachusetts, are waiting for President Trump to make a decision that could change their lives. The president is weighing whether or not to keep his campaign promise to end the Deferred Action for Childhood Arrivals program, known as DACA. The program was signed into law by President Obama as an executive order in 2012. It allows young people who were brought to the country as undocumented immigrants to remain in the U.S. while attending school, without fear of deportation.