LITTLE ROCK, Ark. (AP) — Democrats won’t be able to field a new challenger to Arkansas Republican Sen. Tom Cotton after the previous candidate abruptly dropped out following the filing deadline, the state Democratic party’s chairman said Monday.

Chairman Michael John Gray said the party has been unable to find a way to legally replace Josh Mahony, who ended his candidacy to challenge Cotton two hours after the filing deadline passed, citing a family health concern. Mahony was the only Democrat who had filed to run against Cotton next year.

Arkansas law allows parties to replace an unopposed candidate for nomination because of death or serious illness. Gray said Mahony has provided little information and so they don’t have evidence to support a claim of serious illness that the party could use to field a new candidate.

“With what we have, we do not see a path to put a Democratic candidate on the ballot,” Gray said at a news conference in Little Rock.

Mahony’s exit leaves the party without a candidate at the top of the ticket, though Cotton was widely favored for re-election in the solidly Republican state. Mahony had badly trailed Cotton in fundraising, reporting less than $26,000 in the bank compared to more than $4 million Cotton had on hand. Gray, however, said there were candidates willing to run if the party had been able to find a way to replace Mahony.

Mahony has provided few details about the family health concern, though an attorney for him told the Arkansas Democrat-Gazette that it was a relative and not Mahony who was ill.

Gray said the party was unsure whether the law allowing candidates to be replaced because of a serious illness would cover a family member’s illness but believed it would have been a longshot.

“Absent any information, we don’t even have the opportunity to pursue longshots,” he said.

Mahony last year unsuccessfully challenged Republican U.S. Rep. Steve Womack in northwest Arkansas.

Libertarian candidate Ricky Dale Harrington Jr. and Independent candidate Dan Whitfield have also filed to run against Cotton.