The Tea Party-backed U.S. Senate candidate in Mississippi on Friday appealed a judge's decision to dismiss an election challenge over his Republican primary loss in June.
The appeal, filed in the Mississippi Supreme Court, keeps alive a bitter dispute over a race once seen as a key test of Tea Party clout.
Chris McDaniel, a state senator, lost the Republican nomination in a June 24 runoff by roughly 7,700 votes to Thad Cochran, a six-term incumbent. McDaniel refused to concede, saying that thousands of ballots had been improperly cast by Democrats - most of them African-American - or mishandled by county election officials.
"When the facts are finally heard in a court of law, we believe either the outcome of the election will be overturned or the judge will order a new election," Mitch Tyner, McDaniel's lead attorney, said in a statement.
A Mississippi judge last week dismissed McDaniel's legal challenge over the defeat, finding that he waited too long to file an initial complaint with the state Republican Party.
Cochran's campaign has maintained that McDaniel's challenge is without merit and has said that Cochran has remained focused on the general election, which will be held on Nov. 4.
It is unclear when the state's highest court will act on the appeal.
Travis Childers, a former congressman, is the Democratic nominee for the Senate seat.