Rodríguez, whose district includes part of the city of Miami, is facing a challenge from Republican Daniel Diaz Leyva. The race, which is expected to be tight, is one of the most closely watched in the Florida House.
Regalado hosted the event with former Mayors Manny Diaz, Xavier Suárez and Maurice Ferré.
Former U.S. Sen. Bob Graham also hosted and attended the fundraiser at the Chart House restaurant.
"The guy deserves it," said Suárez, who now sits on the Miami-Dade County Commission. "He's a very good legislator."
The four mayors have different political affiliations. Regalado is a Republican. Suárez is an independent. Diaz and Ferré are Democrats.
Rodríguez called their bi-partisan support "a great honor."
The Florida House hopeful has another reason to thank Ferré. He recently married Ferré's granddaughter, Sonia Succar Ferré.