Just days after Democrat presidential contender Bernie Sanders laid off many of his campaign staff members he grabbed an upset victory in the Indiana primary against rival Hillary Clinton. "I sense a great deal of momentum," Sanders told reporters in New Albany, Indiana, after he won the race.

"While the path is narrow — and I do not deny that for a moment — I think we can pull off one of the great political upsets in the history of the United States."

He added: ''I know that the Clinton campaign thinks this campaign is over. They're wrong. Maybe it's over for the insiders and the party establishment but the voters today in Indiana had a different idea," he told the Associated Press.

Though it's very unlikely Sanders could shake loose Clinton's grasp on the Democratic presidential nomination for the general election, the victory may give Sanders' campaign a second wind and a continued strong push through the primary contests in June into the convention.

A new NBC News-Survey Monkey poll found that 57% of Democrats believe Sanders should stay in the race.

With nearly 96% of the Indiana tally counted, Sanders won 52.5% of the vote to Clinton's 47.5%. He tends to do better in states with open primaries like Indiana, where independents not registered with either party are free to vote for him.

But because the state distributes delegates proportional to votes, it wasn't a big delegate victory for Sanders. The two candidates will essentially split the state's 83 delegates.

Clinton has a lead of roughly 300 pledged delegates over Sanders. Combined with the super-delegates who have vowed to support her at the convention in Philadelphia in July, the front-runner has already secured 90% of what she needs to lock up the nomination.

Sanders, however, has long argued that superdelegates from across the nation — those not bound to any candidate at the Democrat convention — should switch their allegiance to him because he has a better chance in a race against Donald Trump.

Posturing a bit more like his party's pick for the general election, Sander slammed Trump in a speech later in Louisville, Kentucky, where he's already preparing for the 17 May primary there. "I know many of you are fearful of a President Trump," Sanders told about 7,000 supporters, the Louisville Courier Journal reported. "I'm here to tell you, that won't happen. It won't because in every national poll that I have seen for a long time, we beat Trump by double-digit numbers."