Clinton strengthens grip on nomination as six states vote

Hillary Clinton declared victory in the Democratic primary race on Tuesday after fresh wins appeared to seal the party nomination and give her a chance to become America's first female president.

The former first lady took a monumental step toward the White House as US networks declared her the winner in New Jersey and New Mexico, two of six states voting in the last major milestone of the 2016 primary race.

"To every little girl who dreams big: Yes, you can be anything you want - even president. Tonight is for you," Clinton tweeted.

In a speech after winning New Jersey, Clinton said she would be the party's nominee and revelled in what she called a historic moment.

"We're making history - the first time in the nation's history that a woman will be a major party nominee," she said. 

California - the country's largest state - and four other states also vote on Tuesday, but Clinton already has a commanding lead over party rival Bernie Sanders.

Sanders, for his part, has so far been declared the winner in North Dakota and Montana. 

The triumph came almost eight years to the day since Clinton's first White House bid was spectacularly thwarted by a charismatic young senator called Barack Obama.

Two terms later, Clinton may become the first woman to win the nomination of a major US political party, setting up a monumental showdown with billionaire Donald Trump, the Republican flag bearer, in November.

"I feel like we're on the precipice of history, of doing something historic and I wouldn't miss this for the world," said Will Liu, a 30-year-old attending Clinton's victory rally.

"I have goosebumps just thinking about it," he said. 

But like Obama before her, Clinton must first reconcile a bruised and deeply divided party.

Sanders, a self-declared democratic socialist, has said that according to Democratic Party rules, the nominee will not be chosen until the party convention in July. Neither candidate is likely to reach the magic number of 2,383 pledged delegates to officially clinch the nomination ahead of the convention, technically leaving it up to party-chosen superdelegates to decide.

The vast majority of superdelegates are expected to vote for Clinton.

Sanders has harnessed a tidal wave of anger at the ruling political class.

With an insurgent campaign he has gotten much closer to the party nomination than most believed was possible.

An aide said Clinton will later "congratulate Senator Sanders and his supporters on the campaign he has run" in a victory speech to a fired up crowd later in New York later in the evening.

The drive for party unity is likely to receive another shot when Obama comes off the sidelines and offers his own endorsement of Clinton, as soon as Wednesday.

That will not come as surprise, but is an attempt to coax "Bernie or bust" supporters back into the party tent.

Obama has approval ratings above 80 percent with liberal democrats who make up the bulk of Sanders' support.

Trump on offensive

In her speech, Clinton will also take aim at the biggest challenge standing between her and the presidency - Donald Trump.

The millionaire has faltered badly since he won the Republican nomination, with violence-marred rallies, run-ins with the press and a widely condemned racial attack on a federal judge who is investigating his now-defunct Trump University.

Leaders of Trump's own Republican Party described that as textbook racism.

House Speaker Paul Ryan, clearly aware the debacle could do lasting damage to Republican election hopes, called Trump's "racist" attacks "absolutely unacceptable".

Senate Majority Leader Mitch McConnell urged the presumptive Republican nominee to "quit attacking ... various minority groups in the country and get on message".

Trump, who himself won a slew of primary races, signalled Tuesday he plans to go on the offensive against Hillary and Bill Clinton.

"I am going to give a major speech on probably Monday of next week and we're going to be discussing all of the things that have taken place with the Clintons," he said. 

"I think you're going to find it very informative and very very interesting."

Clinton remains mired in scandal about her use of a private email server as secretary of state and perceptions of dishonesty - leaving her with unpopularity ratings surpassed only by the controversial Trump.