(J. Scott Applewhite/ AP Photo | Chris McDaniel For Senate)

A Mississippi judge threw out a lawsuit today filed by Senate candidate Chris McDaniel, who was seeking to overturn Senator Thad Cochran's narrow victory in their June primary runoff.

Judge Hollis McGehee ruled that McDaniel failed to file the challenge within the 20-day period required by Mississippi law.

McGehee's decision was issued a day after hearing arguments regarding the timing of the lawsuit.

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The challenge by McDaniel centered on his frustration over the means by which Cochran won the runoff to their June 3 Republican primary. Refusing to concede his loss, McDaniel argued that he and his campaign team discovered over a thousand ineligible ballots, largely cast by voters who also participated in the state's Democratic primary the day before. Though state law does not require that voters register with a particular party to vote in a primary, it requires voters to align in the runoff with the party they voted for in the primary.

Out of more than 380,000 ballots cast, McDaniel lost to Cochran in the runoff by fewer than 8,000 votes.

McGehee sided with Cochran's lawyers, who referenced a Mississippi Supreme Court Law issued in 1959 that stated election challenges must occur within 20 days of the final day of voting. McDaniel filed the challenge on Aug. 14, well past the deadline.

An aide to McDaniel told ABC News it is currently "unclear" whether they will appeal to a higher court, perhaps the same Supreme Court that issued the law that prevented the successful challenge in the first place.