This would give Clinton and Trump - both New Yorkers – a clear edge over their primary rivals and move them several steps closer to earning the party's nomination for the November general elections, which would decide President Barack Obama's successor to the White House.

However, even a clear-cut win in all of these five states - Maryland, Pennsylvania, Delaware, Connecticut and Rhode Island - is unlikely to make either Clinton or Trump a presumptive nominee, which normally had been the case by now in previous presidential elections.

Trump, who has won 845 delegates so far, is still several hundred delegates short of the required 1,237 delegates. He is followed by Senator Ted Cruz from Texas with 559 delegates and Governor John Kasich with just 148 delegates.

The last two have no mathematical path to reach the 1,237 delegate count before the Republican Convention in Cleveland in July.

 

If you collude in business, or if you collude in the stock market, they put you in jail . But in politics, because it’s a rigged system, because it’s a corrupt enterprise, in politics you’re allowed to collude

 

On the other hand, Clinton has won 1,428 delegates in the primary elections so far and is closely followed by Senator Bernie Sanders with 1,153 delegates.

Clinton has a distinct edge over Sanders in terms of super delegates – who are party officials – and an overwhelming majority of them has pledged their support to her.

As many as 384 delegates are at fray in the Democratic Party, while in Republican 172 delegates are up for grabs today on the eve of which all the five candidates and their campaign teams crisscrossed these states making a last minute pitch.

Addressing his supporters in Rhode Island, Trump lashed out at his two opponents Cruz and Kasich for forging a strategic alliance to defeat him.

"If you collude in business, or if you collude in the stock market, they put you in jail. But in politics, because it’s a rigged system, because it’s a corrupt enterprise, in politics you’re allowed to collude," he said.

Cruz and Kasich appeared to have already conceded defeat in the five states, but said they hope to slow down Trump’s momentum. While Cruz would focus in Indiana, Kasich would devote his entire resources in New Mexico and Oregon.