Two outside groups are flooding St. Petersburg mailboxes with partisan attack ads.
One group connects mayoral candidate Rick Kriseman to the federal government shutdown, while another connects Gov. Rick Scott to the failed fire service fee pushed last year by Mayor Bill Foster.
The intensity and frequency of such negative ads could increase as the nonpartisan race has become the city's most-partisan election.
"It could drive down voter turnout," said Susan MacManus, a political science professor at the University of South Florida.
People could be turned off by unfair attempts to link local candidates to state and national issues, she said.
A mailer recently sent by Tallahassee-based Voter Interest Group asks residents if they are angry about the federal government shutdown.
The group tells voters "they should be furious that someone is working to bring those same failed politics to St. Petersburg" and goes on to describe Kriseman as "negative, divisive and partisan."
Lobbyist and Republican politico David Ramba heads the group. The bulk of its funding since 2012 has come from the Florida Optometric Association, which Ramba represents.
The attack on Foster was sent by Jacksonville's Fact Check Florida and calls the fire fee a "full-blown failure." It says Scott wanted to raise fees for existing services and that Foster tried to "charge us twice" for fire service. "Don't let him fool us twice," it reads near photos of Foster and Scott.
Fact Check Florida was incorporated in July, and has not yet filed a list of donors, records show. The group's chairman, Matthew Martz, has ties to Cesar Fernandez, Kriseman's campaign manager. Both worked on last year's campaign for state Sen. Jeff Clemens.
Both groups are electioneering communications organizations, which don't have limits on contributions or expenditures. They can coordinate with candidates, but not expressly advocate for or against a candidate.
The state GOP and Democratic parties are involved in the race. The Democrats have donated more than $30,000 and are paying Kriseman's campaign manager's salary. The Republicans have assigned a local field director to canvass neighborhoods for Foster and have donated about $7,500 for research.
Both Foster an said they didn't know the mailers were being sent.
"I didn't know I was so powerful," Kriseman said, laughing about the connection to him and the shutdown.
"It was a downright lie," Foster said about connecting the fire fee to Scott.
The attack ads also have increased on the radio and on television. MacManus said some people blame political consultants.
"Their whole training is to go negative," she said. "You have to respond to negative ads. When does the cycle end?"