As voters in a snowy New Hampshire headed for the polls, Bernie Sanders held a 26-point lead over Hillary Clinton in the Democratic while Donald Trump led the Republican field.
With Sanders topping Clinton 61 percent to 35 percent in the final CNN/WMUR tracking poll, most pundits expected the self-styled Democratic Socialist to win the crucial first in the nation vote where independents can participate in either party's primary.
Sanders and Trump are the two candidates who also enjoy the most support from independent voters, according to polls. And with "undeclared" voters making up a little more than 40 percent of registered voters, that margin could make a difference.
In the face of the tough challenge posed by Sanders, Hillary and her husband former president Bill Clinton have sharpened their attacks on the Vermont Senator.
Hillary Clinton noted Sanders has fundraised from Wall Street interests, too, while Bill Clinton ripped Sanders backers for making 'sexist', 'profane' attacks and accused Sanders of derisively labelling opponents as part of the "establishment" when they disagree.
On Republican side of the race, with real estate mogul Trump leading with 31 percent support, the main interest centred on who among the remaining seven candidates would finish second behind him.
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In the final poll, Florida Senator Marco Rubio had 17 percent support, just three points ahead of Iowa caucus winner Texas Senator Ted Cruz at 14 percent.
But he was significantly ahead of the fourth and fifth place candidates in the poll, Ohio Governor John Kasich at 10 percent and former Florida Governor Jeb Bush at 7 percent.
Behind Bush, former HP chief executive Carly Fiorina stood at 5 percent, New Jersey Governor Chris Christie at 4 percent and retired neurosurgeon Ben Carson at 3 percent.
Meanwhile, Trump returned to mocking Bush after the two clashed during ABC's Republican presidential debate on Saturday night, calling him a "loser" and saying "every time he attacks me, he melts like butter."
"You look at Jeb -- Jeb's a loser," Trump said on CBS Monday. "He's spent $110 million so far, he's at the bottom of the pack or toward the bottom of the pack. He's going nowhere. And the only thing he does is attack me."
Bush fired back on twitter later Monday morning, writing, "you aren't just a loser, you are a liar and a whiner. John McCain is a hero. Over and out."
It was a reference to Trump questioning whether McCain -- who spent five years as a prisoner during the Vietnam War -- is a war hero.
Meanwhile, former New York City Mayor Michael Bloomberg added a new twist to the 2016 race by announcing he is considering running for president.
In an interview with Financial Times, the billionaire media mogul also criticised the current candidates saying, "I find the level of discourse and discussion distressingly banal and an outrage and an insult to the voters" and the public deserved "a lot better."
(Arun Kumar can be contacted at arun.kumar@ians.in)