President-elect Donald Trump plans to launch a mass deportation operation targeting millions of immigrants living in the U.S. illegally and with temporary protections once he takes office on Jan. 20, a challenging initiative that could split apart families and affect U.S. businesses.

Advocates say the Social Security Fairness Act rights a decades-old disparity, though it will also further strain Social Security Trust Funds at a time when the program is approaching insolvency.