What party are they?

In keeping up with Bizzyblog's notations of media stories that have no mention of party affiliation, I'm setting up the What Party are They? Label for stories where there is no mention of party affiliation.

The first post originates from Prosaic New Jersey, where former mayor Samuel Rivera, pleaded guilty to corruption charges.

Passaic Mayor Samuel Rivera today pleaded guilty this morning to federal corruption charges and faces up to two years in prison.

Rivera, 61, among 11 public officials caught in a statewide FBI sting last year, pleaded guilty to one count of extortion after being accused of accepting $5,000 in cash from an insurance brokerage firm in exchange for his help getting contracts. The firm turned out to be a front for the FBI.

"Don't worry about it. I'll help you out. I'll help you out," Rivera told an undercover FBI informant last year during one secretly recorded conversation, according to the two-count indictment.

He was indicted earlier this year by a federal grand on bribery and extortion charges. By pleading guilty to the extortion charge, Rivera faces 18 to 24 months in prison under federal sentencing guidelines, according to his lawyer, Henry Klingeman.

You can read the entire article and then answer the question....

What party is he?