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On "America's Election Headquarters" tonight, Karl Rove said that out of the 595 Super Tuesday delegates up for grabs, Donald Trump needs to get as close to 300 as possible.

"The closer that Donald Trump gets to 300, the more this race is over," Rove said.

He explained that Trump doesn't necessarily need to get 300 delegates - which would be 53 percent - but the closer he gets, the better off he will be and the likely it is that he will lock up the nomination.

On the Democratic side, Joe Trippi said that of the 865 available delegates, 475 is the key number for Hillary Clinton.

He explained that the proportional system keeps the delegate count close, but a 475-390 lead over Bernie Sanders would give Clinton a very comfortable lead.

Watch more above.

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