The US Supreme Court has blocked the Trump administration from adding a question on citizenship to the 2020 census for the time being.<br />''<br />''Chief Justice John Roberts joined the court's liberal justices, saying the administration did not provide adequate justification for the question.<br />''<br />''However, the decision left open the possibility that the Trump administration could still seek to make new justifications.<br />''<br />''Trump, who is in Japan for the G20 summit, said on Twitter that government lawyers would now try to have the 2020 census delayed.<br />''<br />''In a separate ruling, the top court's conservative majority refused to rule against electoral redistricting practices, known as gerrymandering, that tend to favour the party in power.<br />''<br />''Held only once every 10 years, the census is instrumental in apportioning some 675 billion US dollars in federal funding to states and cities, and also determines the number of seats allocated to each state in the House of Representatives.<br />''<br />''The American Civil Liberties Union hailed the decision as a victory for immigrants and communities of color across America. <br />''<br />