Washington: The US Democratic Party's presumptive presidential nominee Hillary Clinton has won the primary of the District of Columbia by a comfortable margin. Despite having secured the nomination last week after her win in Puerto Rico and subsequent victories in New Jersey, California, New Mexico and South Dakota, Clinton on Tuesday still had to face the scrutiny of the District of Columbia, a caucus that is favorable towards her due to Washington's socioeconomic composition, EFE news reported. The District of Columbia has a large population of black and Hispanic minorities who are particularly in favour of the former Secretary of State, and is a place of residence of many members of the Democratic Party's "establishment". It proved fertile ground for Clinton's victory, who has had little trouble overcoming her rival Bernie Sanders. In the district there were 20 delegates at stake, most of whom have been allocated to the former First Lady which should help expand her already significant advantage over Sanders, a self-proclaimed democratic socialist. Sanders and Clinton later held a meeting in the federal capital from which practically nothing was resolved, although the veteran senator announced he would address his supporters online in a live stream video on Thursday. The big question since Clinton secured the nomination last week is whether Sanders will retire from the race, or will continue campaigning until the party convention in Philadelphia in July, where the former Secretary of State will be officially nominated. If the senator attends the convention he could use that platform to put pressure on Clinton and the Democratic Party, and try to ensure the issues he has campaigned on - including economic inequality and greater controls on Wall Street - become part of the Democratic agenda.