Trump knocked out his only serious challenger Ted Cruz on Tuesday in Indiana's key primary, winning 53 percent of the vote against 37 percent for the Texas senator, who raised the white flag and surprisingly pulled out of the race.
Over the course of the past 10 months, the 69-year-old Trump -- a Manhattan real estate mogul with no political experience -- has defied the odds, dispatching more than a dozen rivals with more conventional political pedigrees.
‘We'll unify the party. We're going to get people together,’ Trump said Wednesday on Fox News after seizing the mantle of Republican standard-bearer.
‘I think we'll beat Hillary Clinton.’
A new CNN poll looking ahead to the next phase of the White House race however found Clinton, the former secretary of state hoping to become America's first female commander-in-chief, leading the billionaire real estate mogul.
The 68-year-old Clinton has 54 percent support to 41 percent for Trump, the poll showed -- her largest lead since July.
- Cruz's final stand -
Tuesday's contest in the midwestern Hoosier State was the final firewall thrown up by Republican heavyweights to keep the brash, name-calling Trump from locking up the party's nomination.
But as the race was called overwhelmingly in Trump's favor, Cruz conceded to supporters in Indianapolis that he no longer had a viable path forward.
‘We left it all on the field in Indiana,’ Cruz said as he suspended his campaign.
‘We gave it everything we've got, but the voters chose another path.’
It was a stunning denouement for the 45-year-old arch-conservative Texas senator, who had insisted he would press on to the final day of the Republican race.
His departure leaves the low-polling Ohio Governor John Kasich as Trump's only other challenger for the nomination -- making it a virtual certainty that Trump will go head-to-head on November 8 with Clinton.
Having amassed 1,053 delegates, Trump was already in a favorable position to reach the magic number needed to avoid a contested party convention in July. With Cruz out of the race, crossing the threshold is now a foregone conclusion.
‘I believe Donald Trump will ultimately get chosen, and he's going to join the party,’ Republican National Committee chief Reince Priebus said Wednesday, in an extraordinary embrace of a candidate the party establishment had fought tooth and nail to stop.
‘We need to get behind the Republican nominee, and that's what I'm going to try to do for the next several months.’
- 'We're going to fight' -
Clinton, meanwhile, suffered a shock upset in Indiana as her rival Bernie Sanders mounted a come-from-behind victory, denying the former first lady and US senator a feather in her cap as she moves closer to claim her party's nomination.
The self-declared democratic socialist beat Clinton 52.5 percent to 47.5 percent, providing a shot in the arm to his campaign and further justification for staying in a race that Team Clinton and many pundits have said is all but finished.
‘The Clinton campaign thinks this campaign is over. They're wrong,’ Sanders said in a statement.
‘We are in this campaign to win and we're going to fight until the last vote is cast,’ he added.
‘There is nothing I would like more than to take on and defeat Donald Trump, someone who must never become president of this country.’
But the delegate count tells the tale: Clinton is at 2,217 delegates -- just shy of the 2,383 needed to secure the nomination, according to a CNN tally. Sanders is at 1,443. The Democrats hold their party convention in July in Philadelphia.
- Eye on November -
Even before the Indiana results, Trump and Clinton had pivoted toward one another.
‘I'm really focused on moving into the general election,’ Clinton said confidently Tuesday in West Virginia.
‘That's where we have to be because we are going to have a tough campaign against a candidate who'll literally say or do anything,’ she said of Trump. ‘We're going to take him on at every turn.’
Trump meanwhile spoke Wednesday about his potential running mate, saying he wanted someone with ‘political experience.’
‘I would like to have somebody that could truly be good with respect to dealing with the Senate, dealing with Congress, getting legislation passed,’ he told ABC.
Clinton's campaign chairman John Podesta said Trump's propensity to ‘bully and divide Americans’ could backfire with an electorate looking for economic opportunities and to be kept safe.
‘Throughout this campaign, Donald Trump has demonstrated that he's too divisive and lacks the temperament to lead our nation and the free world,’ Podesta said in a statement.
‘With so much at stake, Donald Trump is simply too big of a risk.’