(Reuters) - U.S. Homeland Security Secretary John Kelly signed a memorandum on Thursday rescinding an Obama-era plan to spare some illegal immigrant parents of children who are lawful permanent residents from being deported, the department said in a statement. The program, which was announced by President Barack Obama in 2014, never took effect because it was blocked in federal court.  Obama had hoped that overhauling the U.S. immigration system and resolving the fate of the estimated 11 million people in the country illegally would be part of his presidential legacy.    However, President Donald Trump has vowed to crack down on illegal immigration. The plan unveiled by Obama intended to let roughly 4 million people - those who have lived illegally in the United States at least since 2010, have no criminal record and have children who are U.S. citizens or lawful permanent residents - get into a program that shields them from deportation and supplies work permits. However, it was quickly challenged in court by Republican-governed Texas and 25 other states that argued Obama had overstepped the powers granted to him by the U.S. Constitution by infringing upon the authority of Congress.  A federal appeals court blocked the program, and the U.S. Supreme Court let that ruling stand in a 4-4 split decision last year. Kelly said in a statement on Thursday he was rescinding the initiative, known as DAPA, because “there is no credible path forward to litigate the currently enjoined policy.” An earlier program, Deferred Action for Childhood Arrivals (DACA), offers some 750,000 immigrants brought to the country illegally as children the chance to attend school and to work.  Trump has previously said his administration was devising a policy on how to deal with individuals covered by DACA, but no formal changes have been announced. “They shouldn’t be very worried,” Trump said of DACA recipients in a January ABC News interview. “I do have a big heart.” 