Columbia: Democrats voted Tuesday in the US capital in the final primary of the 2016 presidential race, as the race shifts to the bruising showdown between Hillary Clinton and Republican rival Donald Trump.
With the most controversial primary season in decades drawing to a close, the attention of the nation is elsewhere as it grapples with the aftermath of the Orlando shooting, the deadliest terror attack on US soil since September 11, 2001.
Instead of hailing the end of a historic primary season, Clinton and Trump were trading explosive verbal blows and laying out dramatically different approaches for fighting terrorism in the wake of the gay club massacre in Florida.
While thousands gathered for vigils in US cities in memory of the 49 people killed, the White House hopefuls scrambled to present their proposals for keeping Americans safe.
Trump, the presumptive Republican nominee, on Monday proposed stark changes to existing immigration policy, saying that if elected he would "suspend" immigration from areas with a "proven history of terrorism."
He also suggested American Muslims were complicit in domestic attacks because they failed to "turn in the people who they know are bad."
Clinton, a former secretary of state, maintained a more statesmanlike demeanor, calling on Americans to "stand together" to defeat terrorism.
But after Trump suggested in a TV interview that Obama sympathized with terrorists, Clinton unleashed a blistering anti-Trump broadside and called her rival`s approach "dangerous" and "un-American."
"Even in a time of divided politics, this is way beyond anything that should be said by someone running for president of the United States," she told supporters in Pittsburgh.
"What Donald Trump is saying is shameful," she added. "It is yet more evidence that he is temperamentally unfit and totally unqualified to be commander in chief."Democratic voters in Washington were choosing between Clinton -- who last week reached the magic number of delegates needed to lock up the nomination -- and Senator Bernie Sanders of Vermont.
While Clinton has called for uniting the party quickly in order to focus on the looming Trump battle, Sanders has refused to concede the race.
But he has steadily softened in recent days. The self-declared democratic socialist is due to meet with Clinton later Tuesday to discuss the Democratic Party platform ahead of the national convention next month in Philadelphia.
Sanders told reporters that he wanted to see "the most progressive platform ever passed" at a convention, one which "makes it crystal clear that the Democratic Party is in fact on the side of working people."
"We`re going to take that fight into the convention in Philadelphia," Sanders added.
He met with President Barack Obama last week in a public show of respect for Sanders`s insurgent campaign.
Sanders emerged from the White House declaring his intent to work together with Clinton to defeat Trump in November, a move that should go far to quell concerns of divisions within the party.
Obama endorsed Clinton later that day.
Republicans in Washington held their party convention in March, with Senator Marco Rubio emerging as the top vote-getter.
Tuesday`s vote wraps up a spectacular primary season that saw conservatives flock to a celebrity billionaire and political novice in Trump, as liberals energized little-known Sanders to mount a surprisingly strong challenge against one of the nation`s best-known political figures.
Sanders managed to tap into a deep well of anger among young voters disillusioned by the current political system and eager to see action taken to reduce income inequality, one of Sanders`s main goals.
Clinton ultimately prevailed, becoming the first female presumptive presidential nominee of any major US political party.
The District of Columbia has a large population of African Americans, a constituency that has voted overwhelmingly for her this year.
Sanders is scheduled to address supporters live via webcast late Thursday.