With Tuesday’s primary in Pennsylvania just hours away, Washington Examiner political reporter Salena Zito explained the "three-way tie" between Mehmet Oz, Dave McCormick and Kathy Barnette on "The Story" Monday, examining the impact former President Trump's endorsement will have on the closely-watched Senate race.

SALENA ZITO: You have to begin where the biggest problem lies and that is a weak state party. State parties always have the ability to get the extra candidates out. They didn’t do that in the governor’s race and/or the U.S. Senate race. So you have all of these people sort of vying for their piece of the pie. And their way to get their voice across often happens with running negative ads against each other. A lot of them don’t have a natural base here. So when President Trump endorsed Dr [Mehmet]. Oz, at that moment, Dave McCormick was ahead. When President Trump endorsed Dr. Oz, that switched the dynamics.

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But then, it came to earth and those two were neck-and-neck. Then when President Trump came here 10 days ago…he had a rally. It wasn’t well-attended. Dr. Oz faced some boos because a lot of the base wasn’t quite sure about him. So he sort of went scorched earth with Dave McCormick. That happened at the same time there was a debate in Pennsylvania. Kathy Barnett had some great lines in that debate. All of a sudden, everyone who is exhausted by the fighting went, "Oh, let’s go over here. This looks better." So that’s how we got into this predicament…which is why we’re in a three-way tie right now.

 WATCH THE FULL INTERVIEW HERE: