United States Republican Party front runner Donald Trump has warned there will be riots if he continues to compile the most delegates and the party then fails to name him its nominee.
The controversial businessman has divided his party, with some concerned about his comments against Muslims, immigrants and women and the violence at some of his rallies.
Mr Trump is concerned about reports leaders within the party are now looking for scenarios to deny him the nomination.
Very much the political outsider just 12 months ago, Donald Trump has since racked up a series of primary wins, far more than any other Republican candidate so far.
The outspoken billionaire scored big wins in primaries in four more states on Tuesday, convincing key rival Marco Rubio to drop out of the race.
Republican delegates will choose the party's candidate for the November election at a convention in Cleveland in July.
Under the party's rules, delegates are allocated during the primary process, varying in number from state to state.
Each state votes for its chosen candidates during the series of primaries and caucuses, and the candidate with the most delegates at the end normally gets the party's nomination.
The number of delegates Mr Trump has to amass to secure the nomination is 1,237.
Professor Larry Sabato, from the Centre for Politics at the University of Virginia, says Mr Trump is a firm favourite to gain the most delegates but may not reach that number.
"Here's what the question is now: How close will he come? If he's close to 1,237, I just don't see any way they could deny him the nomination."
But some in the party want to prevent the firebrand businessman from securing the nomination through what is known as a brokered convention.
If he does not secure the 1,237 delegates for automatic selection, the matter will then go to a vote among the delegates between him, Ted Cruz and John Kasich.
In the first round, any delegate whose vote has been won in the primaries and caucuses is obliged to vote for that same candidate.
Those who were pledged to candidates no longer in the race are ineligible.
If Mr Trump secures more than 50 per cent of the vote in the primaries, he could also do well in the first ballot.
But if the winner is not determined in that round, all of the delegates -- including those pledged to Mr Trump -- are then free to vote for any candidate.
Speaking to US network CNN, Mr Trump has warned, if he does not get endorsed to be the candidate, chaos could ensue.
"I think we'll win before getting to the convention, but I can tell you, if we didn't, and if we're 20 votes short or if we're a hundred short, and we're at 1100 and somebody is at 500 or 400 votes -- we're way ahead of everybody -- I don't think you can say that we don't get it automatically. I think you'd have riots. I think you'd have riots."
One area of concern for many in the party is the recent violence seen at Donald Trump's rallies.
Ted Cruz, a senator from Texas, says Mr Trump is responsible for the disruptions taking place at his campaign events.
Parallels have been drawn with the 1968 Democratic National Convention in Chicago, in the midst of the Vietnam War almost half a century ago.
There was no clear winner from the primaries, and the party establishment picked Hubert Humphrey, even though the vast majority of votes had gone to those opposing the war.
Massive protests ensued in the streets of Chicago.
A split within the party then led to Republican Richard Nixon being elected president.
This time, all is calm on the Democratic side.
Hillary Clinton scored a series of big wins over the weekend, virtually ensuring she will get her party's nomination.
Rival Bernie Sanders would need landslide victories to catch up with the former Secretary of State.
Professor Larry Sabato is ready to predict the outcome for the Democrats.
"It's difficult to say this without upsetting the Sanders people, because Bernie Sanders has been putting on a terrific campaign, and, against the odds, he's been doing much better than anybody expected him to do against Hillary Clinton. But the truth of the matter is, this was wrapped up long ago. The nomination is Hillary Clinton's."
