The Florida AFL-CIO (search) split its endorsement Sunday between two Democratic U.S. Senate candidates in a compromise that snubbed Miami-Dade County Mayor Alex Penelas (search).

Neither former state education commissioner Betty Castor (search) nor Rep. Peter Deutsch (search) won the two-thirds vote needed to get a solo endorsement from the federation of unions, but both agreed to the joint endorsement, said Cindy Hall, president of the group, which represents 500,000 workers statewide.

"We have agreed that once the primary is over, we will be with whoever the candidate is," Hall said.

Penelas' snub stemmed from what union leaders described as the mayor's indifference to the alleged mistreatment of protesters at the Free Trade of the Americas (search) meeting last November.

"We had retirees who were thrown to the ground and handcuffed. They had tear gas fired on them," said Rich Templin, a spokesman for the Florida AFL-CIO. "When the smoke cleared, (Penelas) said what a great job law enforcement had done."

Danae Jones, Penelas' campaign spokeswoman, disagreed.

"Mayor Penelas was never indifferent to how protesters were treated," Jones said, adding that Penelas encouraged protesters to file complaints if they thought their civil rights had been violated.

The Democratic candidates, who seek to replace retiring Democratic Sen. Bob Graham, made presentations to union leaders at the labor group's convention in Orlando this weekend. Republican candidates — including Rep. Bill McCollum, former U.S. Housing Secretary Mel Martinez and state House Speaker Johnnie Byrd — were invited but did not attend.

The primary is Aug. 31.