Democratic presidential candidate Hillary Clinton speaks at a rally at Washington High School in Cedar Rapids, Iowa, the United States, Jan. 30, 2016. (Xinhua/Yin Bogu)
U.S. presidential front-runners Donald Trump and Hillary Clinton had huge wins in a spate of primaries Tuesday, which could well seal the deal for their nomination to face off against each other in the 2016 race for the White House, experts said.
Trump, the Republican front-runner, swept all five states -- Pennsylvania, Maryland, Connecticut, Delaware and Rhode Island -- Tuesday, effectively stopping rival Senator Ted Cruz in his tracks and putting himself perhaps within just a couple of states of clinching the Republican Party (GOP) nomination.
Clinton, the Democratic front-runner, also won big Tuesday, winning four states, and experts said the victories mean she will be the Democratic nominee.
"Clinton sealed the deal last night," Brookings Institution's senior fellow Darrell West told Xinhua. "She has 90 percent of the delegates she needs for the nomination and will get them very soon."
"Trump had a great night and moved much closer to the GOP nomination. It is going to be difficult for party elites to withhold the nomination from him even if he is a few delegates short," he said.
Indeed, there had been talk in recent weeks that the GOP establishment would attempt to withhold the nomination if Trump does not grab all 1,237 of the required delegates, but that seems unlikely now, experts said.
Dan Mahaffee, an analyst with the Center for the Study of the Presidency and Congress, echoed those thoughts.
"Trump's big win means that he will, in all likelihood, be the GOP nominee, as momentum and mathematics continue to work in his favor," Mahaffee told Xinhua. "He could be as few as two states away from victory, with New Jersey and West Virginia looking to be in his favor. Cruz will continue to emphasize Indiana, but that won't be enough to stop Trump, and California is increasingly looking to be in Trump's favor."
"Cruz's hope of denying Trump the 1,237 looks increasingly remote," Mahaffee said.
The next round is in New Jersey and California, where Trump is expected to do well.
"He is expected to do well in New Jersey and California and if he can add Indiana to his side next week, he probably will be unstoppable. All of the attacks against him have failed and slowly the party is coming around to his candidacy," West noted.
For her part, Clinton, now practically assured of the nomination, is turning her attention away from rival Senator Bernie Sanders and honing in on Trump.
"She will focus on the billionaire in her future speeches and attempt to make Sanders' voters more comfortable with her. Trump will help her unify the party behind her," West said.
Mahaffee said that for Clinton, it's time to look to the general election. "Her inevitable victory on the Democratic side is now just that more inevitable," he said.
Republican strategist Ford O' Connell told Xinhua that now Trump has a definite shot at beating Clinton in the race for the White House. But to do so, he needs to tone down the bombastic and offensive rhetoric. While his manner of speaking has gained him popularity among his base, it will have to be toned down to make him more appealing to others.
Indeed, Trump has referred to Mexican immigrants as "rapists" and said Muslims should not be allowed into the U.S. He has also made derogatory comments about women.
Some experts said Trump needs to reign in his sharp tongue in order to be competitive in the general election.
"He doesn't need to make a 180 (degrees). If he would just bend around 45 degrees he could actually win this thing," O'Connell said of Trump.
