But less than a month before the May 2004 primary election, Esposito dropped out, saying he had to withdraw because of his ailing mother-in-law.
The real reason surfaced only later: The FBI had planted Esposito among the field of candidates to help find evidence of vote-buying in southern West Virginia.
Federal prosecutors say the gambit worked.
They allege Esposito gave $2,000 in government-supplied money to a resident who had offered to bribe voters on his behalf.
They also credit the undercover sting operation for last year's guilty pleas by the sheriff of Logan County and the police chief in the coal-mining city of Logan, who both admitted to election violations.
The chief judge of West Virginia's southern federal court district condoned the tactic Thursday in an election fraud case against Perry French Harvey Jr., the man who allegedly accepted the $2,000.
Judge David Faber rejected arguments from Harvey's lawyer that the government had acted improperly by putting up a sham candidate.
Esposito, 54, began cooperating with investigators in July 2003, when he agreed to plead guilty to a federal corruption charge. Esposito, an attorney, had failed to notify authorities of criminal activities involving a former county magistrate.