The country’s most dynamic and progressive union coalition – The Los Angeles County Federation of Labor–finds itself in a world of pain this week, just a few months out from a looming hotel workers’ showdown.

Earlier this week, the charismatic County Fed leader Martin Ludlow – a close ally of L.A. Mayor Antonio Villaraigosa–was forced to resign under the cloud of a criminal investigation. Ludlow reportedly took a plea deal to avoid jail by stepping down after a multi-agency probe turned up evidence that he violated campaign laws when he accepted undisclosed union phone banking support during his 2003 election to the City Council.

This is the second shock to the 800,000 member County Fed in less than a year. Last May, its highly successful leader, Miguel Contreras, died of a sudden heart attack. Contreras had forged the Fed into a political powerhouse whose endorsement was readily sought by aspiring candidates. Contreras, however, had thrown the Fed’s support to then-incumbent Mayor James Hahn against challenger Villaraigosa. It was a decision that had deeply split labor ranks; Villaraigosa, a former union organizer, had been considered labor’s best friend and seemed the natural favorite for the Fed.

In an ironic twist, Contreras died just days before Villaraigosa’s election. In order to mend fences, the County Fed then turned to 41 year old African-American Ludlow–who had been an aide to Villaraigosa–to take over the helm of the organization.

Ludlow artfully held the County Fed together even as its national affiliates went through a divorce last year that split up the AFL-CIO.

His forced resignation has now tossed the union alliance into a deep crisis. In the last few days there had been open speculation that Contreras’ widow – hotel workers’ leader Maria Elena Durazo–would be given the top post. But a two hour meeting of the County Fed on Thursday ended inconclusively. Another possible contender is Kent Wong, the popular leader of the UCLA labor center. There’s no word when the Fed will meet again to try to elect a new head.