Republican billionaire Donald Trump and Democratic power player Hillary Clinton look set for an ugly battle for the White House in November's US presidential election after a bruising season of primaries. Trump knocked out his only serious challenger, Ted Cruz, on Tuesday in Indiana's key primary, winning 53% of the vote against 37% for the Texas senator, who raised the white flag and pulled out of the race.Over the course of the past 10 months, the 69-year-old Trump has defied the odds, dispatching more than a dozen rivals."We'll unify the party. We're going to get people together," Trump said yesterday on Fox News after seizing the mantle of Republican standard-bearer. "We'll beat Hillary Clinton."A new CNN poll looking ahead to the next phase of the White House race, found that Clinton, the former secretary of state hoping to become the US's first female commander-in-chief, is leading the real estate mogul.The 68-year-old Clinton has 54% support to 41% for Trump, the poll showed - her biggest lead since July. Clinton suffered a shock upset in Indiana when 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.Clinton is at 2217 delegates - just shy of the 2383 needed to secure the nomination, according to a CNN tally.Sanders has won 1443 delegates. - AFP..